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VJSC 2009 1 VJSC 2009 2 VJSC 2009 Providing our Food for the weekend. Dr Karl Kruszelnicki Books for the Receipt Number Lucky Draw. TROY CAPITAL (dealing with Financial planning) First Aid for the Challenge 3 VJSC 2009 Welcome In 1985 Professor Veronica James set up and ran the first of what became the Annual Science Camp for Hearing Impaired Children. Veronica herself very clearly explained why she began these science camps and why they needed to continue. “I became aware that very few hearing impaired students actually progressed to tertiary studies, particularly in the sciences. Hearing impairment is no barrier to studying these subjects and, because language is acquired as needed, these are some of the easier subjects for a hearing impaired student to study. Times have not changed. Hearing impaired students are still often deprived of the chance to study science and mathematics because their teachers consider that extra time is needed to help develop language and assume that these students will never need mathematics or science skills.” Many people have brought this weekend into being and we need to mention the following: The Committee of Volunteers who make it all happen. Dr. Murat Kekic, Helen and David Hammersley, Marjorie and Geoffrey White, Shane Hengst, Mikayla Keen, Shila Jeram, Sally Peacock, Ankur Chaudhary, Pia Doss, Dr. Hooi Toh, Gregory Staib, Louise Rakowski, Juliet Schumacher, Sue Boyd and Bryan Johnson. 4 VJSC 2009 The Head Tutors who prepare and lead the Lessons and the Tutors who assist them. The ladies of Quota International 35th Division for providing us with delicious, much needed, food. And most important thanks go to the University of Sydney, Faculty of Medicine, Discipline of Pathology, for accepting responsibility for the Science Challenge. Currently there are many hearing-impaired and deaf tutors helping out and, most importantly, going to university. University is not the answer for everyone, but it should not be dismissed as a legitimate option for those people who would like to go. Deafness and wearing of hearing aids is definitely not a barrier, so make sure that you don’t make it become a barrier, as the biggest limitation to your future will be the limits you put on yourself. 5 VJSC 2009 A Message from the Faculty of Medicine By Dr. Murat Kekic The Faculty of Medicine (Discipline of Pathology) is proud to host the 2009 Veronica James Science Challenge for Hearing Impaired Children. The Faculty of Medicine at the University of Sydney is Australia's oldest and largest medical faculty undertaking teaching and research in health and medicine of international standing. The Faculty of Medicine is part of the University's College of Health Sciences, the largest and most comprehensive grouping of health and medical education research in the Asia Pacific region. The Discipline of Pathology is Part of the Faculty of Medicine. It has been teaching Pathology to students since 1883. Dr Murat Kekic is the Department Manager of Pathology, as well as the Curator of the Pathology Museum. 6 VJSC 2009 In Memory of Judy Gray 20 July 1961 –9 March 2009 ! " # $% % & '% ' ' " ( )"" 'I do not have to live forever to have lived my fairy tale. Every day is a bonus - Judy' 7 VJSC 2009 8 VJSC 2009 Maps for Science Challenge 2009 9 VJSC 2009 10 VJSC 2009 Lesson Index No.Lesson 1 2 3 4 5 6 7 8 9 10 Location Art StarLab Web2Spider Mirrors Kidney Dissection First Aid Viscosity Slime Science in the Kitchen Molymods Bosch, Room 192 ground floor Lecture Theatres Bosch Foyer ground floor Lecture Theatres Blackburn Building, Level 1, Room 110 Blackburn Building, Level 1, Room 109 Blackburn Building, Level 6, Room 625 Blackburn Building, Level 5, Room 570 Blackburn Building, Level 5, Room 565 Blackburn Building, Level 4, Room 425 Blackburn Building, Level 4, Room 425 Blackburn Building, Level 4, Room 412 Timetable Saturday 9:30 - 10:15 10.15 - 11:00 11:00 – 11:30 11:30 – 12:15 12:15 – 1:00 1:00 – 2:00 2:00 – 2:45 2:45 – 3:30 Sunday 9:30 – 10:15 10:15 – 11:00 11:00 -11:30 11:30 – 12:15 12:15 – 1:00 1:00 – 2:00 2 :00 - 1 2 3 4 1 10 2 1 3 2 4 3 9 8 10 9 1 10 2 1 7 6 8 7 9 8 10 9 Group Number 5 6 Lesson Number 5 6 4 5 Morning Tea 3 4 2 3 Lunch 1 2 10 1 7 8 9 10 7 6 8 7 9 8 10 9 5 4 6 5 7 6 8 7 3 2 4 3 5 4 6 5 Group Number 1 2 3 4 5 6 7 8 9 10 Lesson Number 5 6 7 8 9 10 1 2 3 4 4 5 6 7 8 9 10 1 2 3 Morning Tea 3 4 5 6 7 8 9 10 1 2 2 3 4 5 6 7 8 9 10 1 Lunch Prize-giving Ceremony in Bosch 1A LT1 Students to sit in rows according to group, starting with Group One at Row one. Parents to sit at side or rear seats. 11 VJSC 2009 Table of Contents 1. Art … Pg. 13 2. StarLab … Pg. 15 3. Web2Spider … Pg. 31 4. Mirrors … Pg. 43 5. Kidney Dissection … Pg. 57 6. First Aid … Pg. 65 7. Viscosity & Density … Pg. 75 8. Slime … Pg. 81 9. Science in the Kitchen … Pg. 85 10. Molymods … Pg. 95 12 VJSC 2009 LESSON 1 ART HEAD TUTORS: KEITH AND WENDY NORRIS 13 VJSC 2009 SEED SELECTION & SAVING The seed of a plant is a very complex structure, containing a partly formed plant (the embryo consisting of a stem bearing a bud, a root and one or more seed leaves), a food supply (the endosperm) and a tough, protective outer covering (called the seed coat or testa). Once a seed has been formed in a parent plant, the embryo ceases to develop and development is not resumed until the seed germinates. Seed sowing is by far the simplest most economical method of propagation vast numbers of trees and produces plants with taproot systems. It is also the best means of propagating most shortlived plants (e.g. flowering annuals, biennials and vegetables). More over, it can be used for a number of plants (e.g. eucalypts and acacias) for which, as yet, no reliable vegetative propagation is possible. Collecting seeds from Australian native trees and shrubs is a simple exercise and can be done through the year. Some plants (e.g. acacias and eucalypts) release their seeds only at certain times, others (e.g. callistemons) have seed capsules all the year round. The seed capsules should be collected as they mature (turn a honey colour). Placed in a brown paper bag and hung up to dry in a warm, airy situation. After a few days the woody case will shrink and the seeds will be released. Collected seeds not sown immediately must be stored correctly, otherwise the germination rate will not be as high as it should be. Although the seed is dormant (i.e. at a resting stage in its life), it is alive and capable of developing when exposed to warmth and moisture, and sometimes to light. To store seeds, select a cool, dry and airy location of even temperature. Do not store selfcollected seeds in air- tight containers. Preferably, use paper bags or the boxes made of card as shown in diagram. Label with plant name, date and place collected. It is recommended that seeds be sown within one year of collection. 14 VJSC 2009 LESSON 2 STARLAB HEAD TUTOR: SHANE HENGST 15 VJSC 2009 STARLAB International Year of Astronomy 16 VJSC 2009 The United Nations has declared 2009 the ‘International Year of Astronomy’. 400 years ago in the year 1609, Galileo Galilei pointed his telescope to sky for the first time and changed the way we look at the universe. Galileo is considered to be one of the first pioneers of ‘Science’ of the modern era. His observations in 1610 showed bodies going around Jupiter instead of our own Earth! Thus, presenting evidence that falsified the geo-centric (or Earth-centred) model that the majority of people believed in at the time. Unfortunately for Galileo, the geo-centric doctrine was backed by the Church and as such was placed under house arrest for his twilight years. Galileo was among the first people to present evidence to falsify a theory in order to present a new one in its place. Thus, starting off evidencebased research that today Scientists still use to justify their research. 17 VJSC 2009 The Universe in which live We reside on Earth, spinning on its axis (23 degrees) at approx. 1400km/hr, which is revolving around our Sun. The Earth and Sun are part of a solar system, made up of 7 other (official) planets. Our solar system revolves around the common centre of a spiral galaxy that contains a few hundred billion stars. The spiral galaxy is known as the Milky Way. Earth and Sun relationship In relation to the Sun’s own rotation the Earth rotates on a tilt. So, as the Earth revolves around the Sun, the Sun’s rays penetrate different sides of the Earth. The relative surface temperature is largely dependent on the incident angle of the Sun’s rays. For figure below represent a basic model of the Earth revolving around the Sun in two ‘snapshot’ positions 1 and 2. The figure shows the relative tilt of the Earth with a dot representing a location on the Earth, let say Sydney. In position 1, the Sun’s rays 18 VJSC 2009 penetrate the atmosphere directly above Sydney. The corresponding season for Sydney is then summer. When the Earth is in position 2, then Sun’s ray penetrates Sydney’s atmosphere at an angle, resulting in winter. Now, since Sydney in the southern hemisphere, cities in the northern hemisphere result in winter at position 1 and summer in position 2. Therefore, it is the angle of the Sun’s rays penetrating the atmosphere, due to the Earth’s tilt, that determines the seasons on Earth. Sydney’s latitude is about 33 degrees south of the equator, south celestial pole: point in the sky where the stars rotate around Why is the sky blue? A very common question… the atmosphere that surrounds Earth contains many types of gases, tons of nitrogen, a lot of oxygen along with other molecules. When the Sun’s rays strike the atmosphere, it is absorbed by the oxygen molecules and then is scattered in all directions. It turns out that the oxygen molecules resonates with the same frequency as blue light (see Nature of Light section), thus, blue sky during the day. Of course, the blue sky can be hindered by clouds but that is another effect. Furthermore, if you ever notice with sunrises and sunsets the sky around the Sun appears redder. This is because the Sun’s rays are now resonating with the dust molecules (corresponding to same frequency as red light) in 19 VJSC 2009 the air just above the ground. As the Sun completely sets, then there is no direct sunlight and thus a clear window to the stars can now be seen. Night Sky Constellations In the modern day catalogue there are 88 constellations not all can be seen at once. A constellation is defined by a group stars that represents an object or living thing. The constellation of Sagittarius is roughly the centre of our galaxy. The Ecliptic Currently, it is said that the Solar System consists of the Sun and 8 planets. (As of 2006, astronomers declared Pluto to be a ‘dwarf planet’). The Sun, relatively speaking, resides at the centre of the Solar System whilst all the other planets roughly orbit the Sun in concentric nearly-circular paths. (See image). The planets don’t exactly orbit the Sun but rather orbit around a common centre of mass called the ‘Baryonic Centre of Mass’ (even the Sun orbits this point!). As an observer on Earth, it would appear that the Sun, the Moon and all the other planets follow an imaginary line called the Ecliptic (rising in the east and setting in the west). 20 VJSC 2009 The Zodiac Constellations The constellations of the Zodiac reside on along the ecliptic. While not commonly referred to in the Astronomy catalogue but rather than in Astrology; and as such an Astrologer will define your Zodiac constellation when the Sun is in a particular constellation (viewed from the Earth) when you are born. To an astronomer, they have a similar definition of the Zodiac, although these constellations were made over 2000 years ago and as such the stars, our Sun, and the planets have progressed through space during this time. As a result, it turns out that the Sun’s path along the ‘ecliptic’ travels through an additional constellation called Ophiuchus, known as the ‘Serpent Keeper’. 21 VJSC 2009 Navigation Sailing ship captains back in the day used the stars to navigate. In the Northern Hemisphere it was easier to find North by using the North Star, that corresponds to the northern celestial pole. Finding south using the Southern Cross and the Pointers: This method finds the south celestial pole: a point in the sky where the stars appear to ‘orbit’. Sydney’s latitude is about 33 degrees south of the equator and the south celestial pole is also about 33 degrees in elevation. 22 VJSC 2009 Stars An astronomer’s perspective Cataloguing When naming a star, it is usually done by taking the suffix to be the constellation that they are in and the prefix is based on the Greek alphabet – alpha = brightest, beta = second brightest and so on. Brightness Stars can vary from being very dim to very bright. A star is dependent on both the amount of fuel and the distance from Earth. Stars can also vary their brightness over time and they are known as ‘Cepheid’ variable stars. These types of stars can determine how their distance from Earth. The brightest star in the Night Sky is Sirius. Colour The colour of the stars is dependent on how hot they are. They also indicate their relative age to each other. Blue Stars Hot and Young! Surface Temp: ~25,000oC to ~100,000oC 23 VJSC 2009 Yellow Stars Warm and Middle-Aged! Surface Temp: ~6000K Red Stars Cool and Old! Surface Temp: ~3000K 24 VJSC 2009 Milky Way A galaxy is defined as a system of billions of stars, which is held together by a mutual gravitational attraction. The larger galaxies are thought to be driven by a super-massive black hole. The Milky Way galaxy is approximately 100,000 light years across that has about 200 billion stars. Our Milky Way is one of the most dominant galaxies in our local group that contains 40 galaxies (which includes LMC, SMC and the Andromeda galaxy). It is thought that our ‘Milky Way’ galaxy is barred spiral galaxy that is part of local group galaxies. There are literally billions upon billions of galaxies teaming in the Universe, the exact number, we don’t know and probably won’t know. (see section on ‘Measuring up the Universe’) 25 VJSC 2009 Nature of Light What is Light? Light is usually termed to what we can see with our own naked eyes. A scientific definition is broader and specific. When I say broader, I mean does not just includes the visible light but also includes: radio, IR, UV, X-rays and gamma-rays (see image); and when I say specific, I mean that light comes in something called ‘electro-magnetic’ energy, which come in all different ‘sizes’. These ‘sizes’ determine if they are IR, UV, etc. To be precise, the ‘size’ is defined by its frequency (or its wavelength). To explain: one way to ‘look’ at light is by observing its corresponding waveform: λ Note that this is only model of the waveform and can be expressed mathematically. Also, that waveform is continuous and repetitive. Velocity = Frequency times Wavelength V=fxλ V = speed of light (universal speed limit) λ = wavelength (length of waveform – i.e. length of one revolution) f = frequency (how often the wavelength passes a specific point in space per second) 26 VJSC 2009 Measuring up the Universe Distances: A light year is the common unit we use to measure distances to the stars. A light year is defined by how far light travels in one year. The speed of light is approximately 300 000 00 metres per second (or 1.8 million km/h). Our closest star called Alpha-Centauri (one of the pointer stars) is about 4.3 light years away. It takes a finite time to reach us, which means that it took four-and-a-bit years for the light from Alpha-Centauri to reach Earth. That means we are always looking into the past, which also means, that these objects may or may not still exist. INTERESTING FACT: It takes about 8 minutes for light to reach us from the Sun, which means that if the Sun exploded at this instance, we won’t know about it until 8 minutes later. Historical Perspective: As a result of the finite speed of light, with all light that we see, we are always looking into the past. 27 VJSC 2009 Big Bang Theory The general consensus now says that the universe began with a ‘big bang’ of which everything suddenly expanded from a single point. It turns out Astronomers can look back as far 300,000 years after the big bang where we see a glow in the microwave regime with tiny temperature variations that corresponds to the birth places of what is thought to be galaxies. This is known as the Cosmic Microwave Background (CMB, see image). The CMB is very close to the ‘edge’ of the observable universe and it is determined to be about 14 billion light years back in time. Note, again, that this is measurement of time not distance. Thus, this there is a limit to our observable universe. The exact size of the physical universe is not known and probably will not know because we can look into a time ‘bubble’ of the universe. 28 VJSC 2009 Are we alone? Scientists believe since that life evolved here on Earth, there is the likelihood of finding life elsewhere in the universe. There are several methods of finding the possibility of life beyond our solar system: Our Solar System & Exoplanets It turns out that our solar system is unique because no astronomer has yet to discover an Earth-like planet around another star system. A planet around a star, other than our own Sun, is called an extra-solar planet (or exo-planet for short). As of March of this year (2009), there has been a sum of 344 exo-planets discovered; however, none as yet exhibits the same properties to that of Earth. The Search for Extra-Terrestrial Intelligence (SETI) “SETI … is an exploratory science that seeks evidence of life in the universe by looking for signature of tis technology.” A common example of finding such signatures is by listening out for radio signals from distance civilisations. So far we haven’t heard anything… BUT THE UNIVERSE IS REALLY, REALLY, REALLY BIG!!!!! 29 VJSC 2009 So, it begs the question: ARE WE ALONE? What are the possibilities…? “If it is just us, it seems like an awful waste of space” Contact – written by Carl Sagan 30 VJSC 2009 LESSON 3 WEB2SPIDER HEAD TUTOR: GREGORY STAIB 31 VJSC 2009 Web2Spider 32 VJSC 2009 Lesson Objectives Background There are over 34, 000 identified species of spiders in the world, and, to assist scientists in classifying species they are grouped into approximately 100 families. Australia hosts extremely high biodiversity of spiders with approximately 80 of the recognised spider families living here. About 3330 Australian species have been described so far; with more than 6000 still awaiting description. The sp ders that use their silk producing ability to construct prey-catching webs (‘orb-webs’) are the ones of interest to us. Depending on the type of spider orb-webs can vary in size, shape, orientation, patterns, and the type of silk used. These differences between spider webs allow us to identify the type of spider that built it. Today you will receive a data sheet explaining the characteristics of 19 orb weaving spiders provided by the Australian Museum. To identify the spiders we find you will also be using a ‘dichotomous key’ which is similar to a flow chart. We will be going to a few different areas and a data sheet has been included for you to tally up which spiders you find in each area. Before we begin we need to learn a few spider facts so that we know what features of a spider’s web to look out for. It is important that nobody touches the spiders in their webs. Although the spiders we are looking at today are not poisonous to humans they play a vital role in the ecosystem and it is important to be aware and respectful of this, and not disturb their webs. DO NOT TOUCH ANY OF THE SPIDERS OR THEIR WEBS!!!!!!!!!! Identifying Elements of a Spider Web The most basic part of a spider’s web that we may notice are the threads coming out from a central hub, called the radius threads. Circling around the radius threads is the silk that the spider uses to catch inscets, this is called the spiral. The basic scaffolding that the spider uses in constructing its web to anchor it to the earth are the frame threads. Figure 1 on the following page shows an incomplete orb-web displaying these elements. The section of a spider’s web between two radial threads (highlighted red) is known as segment. Some spider webs like that shown in figure 2 may have a signal line. The spider may sit outside the web perhaps under the cover of a curled leaf to protect them from birds and wait for insects to fly into the web. The web will start vibrating as the insect struggles, and, because the spider has this signal line they will be able to quickly go wrap their dinner. Figure 1 and figure 2 are examples of spider’s webs that we define as ‘incomplete’ although in figure 2 it is only a pie slice or segment that is missing. The hub in both these figures is approximately in the centre of the web but sometimes (as you may see in the field) it can be quite offset. 33 VJSC 2009 Figure 1 Figure 2 Some spider webs have different orientations. That is to say they may be horizontal or vertical to us in orientation and this is due to different spider species building webs for the capture of specific prey types. Spider webs may have different decorations in the hub and again this depends on the type of species. Figure 3 shows some different decorations that you may encounter in the field today. A glossary is also included at the end of this lesson with further descriptions. Figure 3 34 VJSC 2009 Spider Identification Table (Summary) The following table shows the most likely spider that you will find when viewing any of the 19 different web types. Some web types for example W2 have two spiders associated with it. This is because the webs that these two spiders are very similar so that further work is necessary before it can correctly be identified. The data sheet you will have with you in the field will be of assistance if this happens. Web Type W1 W2 W3 W4 W5 W6 W7 W8 W9 W10 W11 W12 W13 W14 W15 W16 W17 W18 W19 Spider Name Argiope keyserlingi Araneus Argiope protensa Zosis Cyclosa Argiope Cyclosa Cylcosa Austracantha minax Phonognatha graeffei Araneus dimidiatus Nephila Arachnura higginsi Phonognatha graeffei Philopenella Nephila See others Eiophora Tetragnatha Leucauge Common Name St Andrew’s Cross spider Young St Andrew’s Cross spider Jewel spider, Christmas spider Leaf-curling spider Leaf-curling spider Golden orb spider Scorpion tailed spider Leaf-curling spider (young) Signal-line spider Golden orb spider (young) Garden orp spider Long-jawed spider Silver orb spider On the following page is a copy of the dichotomous key that you will be using in the field to identify the spider from the web that you are looking at. One is to use when you are observing a complete orb web and the other for orb webs with missing sections. We will go through an example of a spider’s web using this key before we set of. 35 VJSC 2009 36 VJSC 2009 37 VJSC 2009 Example using the Spider Key Charts: Is it a complete web or a web with missing segments? Missing segments Is there a rolled leaf in the web or is it without a rolled leaf? _________ Is there a signal line? _________ Is there a ‘pie slice’ or missing segment? _________ Is the hub in the centre or offset? _________ Does it look like there are more or less than 20 radials in a 90 degree segment? (compare with figure 2) _________ OUR SPIDER IS…. 38 VJSC 2009 Web2Spider Data Sheet Location: Weather Conditions: Date: Time: Tallies Web Type W1 W2 W3 W4 W5 W6 W7 W8 W9 W10 W11 W12 W13 W14 Area 1 Area 2 Area 3 Area 4 39 VJSC 2009 More Field Exercises (If time permits) Draw some decorations you see in the hub of some of your identified spiders or some of their webs. Spider Web Type: Spider Web Type: Spider Web Type: Spider Web Type: 40 VJSC 2009 Glossary A barrier web, also known as a labyrinth, is a haphazard series of silk lines in front of and/or behind an orb web. These are thought to help deter and detect predators. The lines may also help to disorient flying prey, making them more likely to fly into the orb, which is the catching part of the web. Catching surface: the area of an orb web that is covered by spirals or switchbacks of sticky, stretchy silk. In missing sector webs, the missing sector is defined by not having this catching surface, although a tangle of lines may fill the gap. Debris refers to the remains of the spider’s meals and sometimes small scraps of leaves and bark that are incorporated into webs and retreats. Some spiders join these bits in a line and hang it from the web, whereas others attach it to the surface of the web using conspicuous white silk. Retreats may also be made from, or incorporate, debris. Decorations are silk patterns, or sometimes the silk-wrapped remains of the spider’s meals (debris), which are woven onto the surface of the orb web. If examined closely the silk patterns often zigzag. Fan: indicating the shape of a hand fan. Extending out from a central point. Hammock: what we have termed here a hammock web is a sheet web that is suspended like a trampoline or circus safety net. The main supports and stabilising lines are around the edge and below the sheet and the centre is lower than the edges. There is often a tangle below the sheet where the spider waits for prey. Horizontal: see orientation The hub is the central area of an orb web. This is typically an irregularly woven area where the radial support lines meet and are joined together. Some spiders eat away part of this area when they have finished making the sticky spiral. A knockdown web is a tangle of lines above or below a sheet web which disorients or intercepts flying insects so they land or fall onto the sheet. Like barrier webs, knockdown webs probably also serve a protective function by preventing predators such as wasps from easily flying in. Lace webs do not contain sticky silk, instead they capture prey by snagging. Each line is composed of many tiny fibres which are combed to produce an entangling fuzzy thread, rather like a fluffed out strand of wool or cotton. The web is constructed in a characteristic pattern of ladder-like sections with zigzag steps. New regions show this clearly, but as the web ages, this structure decomposes, and sometimes new layers are laid over the old. Eventually the structure of old areas of the web appears as a jumble of different-sized squares, rectangles and circles. A nest can be considered as a glorified retreat. Here we are specifically referring to the densely woven home of a particular kind of spider. These are often solitary, in which case the nest may be small, but sometimes they live communally, and the large nest may contain up to one hundred or more spiders. Orientation: vertical, horizontal or sloping. These are all terms used to describe how an orb web is positioned. Using a bicycle wheel as a model, ‘vertical’ would refer to the normal orientation with the bicycle held upright ready for use. ‘Horizontal’ would apply if the bicycle were lying on its side, or ‘sloping’ if it were angled from being leant against a low wall or post. Platform webs are a kind of sheet web. The sheet is gently to steeply sloping up and out from the spider’s retreat, which is in a silk-lined burrow. The sheet is pulled taut into a smooth surface, which the spider runs on. This is the platform. Above the platform is a maze of knockdown lines. 41 VJSC 2009 Radials are the silk lines that radiate from the centre of an orb web to the outer frame or support lines like the spokes of a wheel. They are the framework on which the catching spiral is laid. A retreat is a hideaway where the owner of the web may be lurking. This is typically a dead, curled leaf; a hole in a dead twig; or pieces of debris joined to form a tube, which is bound with silk. Sometimes the retreat is just a denser area of silk lines woven into a tunnel, which is usually against a twig or leaf. Often there is a protective tangle of lines around the retreat area, which can make it look like a separate web. Sector: if you think of the radial lines that go from the centre of an orb web to the frame as being like the spokes of a wheel, then the area between each spoke is a sector (like a pie slice). ‘Missing sectors’ might be filled in with a tangle, but there are rarely any catching spirals through them. The catching spirals either form a U-turn to either side or end abruptly. A sheet is a closely woven mesh of non-sticky silk lines. Sheet webs can be simply guyed out to the adjacent substrate, e.g. vegetation etc., or associated with a tangle of vertical or haphazardly orientated lines. The sheet part can be seen as a distinct flat or curving surface among the supporting lines. Dew, or a fine spray of water droplets, shows a sheet up clearly. A signal line allows the spider to hide away from an orb web in relative safety, whilst allowing it to monitor the web in case prey flies in. The signal line is usually attached in the hub area at one end and can be followed to the spider’s retreat at the other. One leg of the spider can often be seen resting on the line. Silk is composed of thin, strong protein fibres. Silks are produced by a number of invertebrates, including caterpillars such as the ‘silkworm’ and spiders. Whereas the caterpillars and other insects mostly use silk to make a nest or a cocoon, spiders have adapted silk for all kinds of purposes. These include the covering for egg sacs, for making secure retreats and, of course making webs. Spider silk is spun from the spinnerets, on the tip of the spider’s abdomen. Several different kinds are made, including combed fluffy silk (cribellate silk) which is used in lace webs, strong non-sticky threads like those that support orb webs and the sticky silk that is coated with viscous droplets and makes up the catching spiral on many orb webs. Sloping: see orientation. Spirals form the catching surface of a typical orb web. Sometimes there is literally one continuous spiral from the outer edge of the web into the hub. In other webs there may be breaks, or the catching thread may reverse direction once or many times. In most orb webs the spirals are made of sticky silk that is coated in glue-like droplets. A few kinds of orb webs have catching silk of a different nature (cribellate silk). This cannot be as highly tensioned as sticky silk, and so these webs often appear untidy and ‘floppy’. A tangle is a more-or-less unstructured and haphazard collection of silk lines without other features like an orb or a sheet. As a guide, we have defined a simple tangle web as anything over five lines in roughly a 10 x 10 x 10 cm area. When tangles are a part of a different web type they usually have a special name; for example, a system of haphazard lines placed on either side of on orb or below it is usually called a ‘labyrinth’ or ‘barrier web’ and a similar tangle above a sheet web is often called a ‘knockdown web’. Vertical: see orientation. References Web2Spider package prepared by the Australian Museum. Foelix, R.F, Biology of Spiders, 1996 Further information can be found at www.bugwise.net.au 42 VJSC 2009 LESSON 4 MIRRORS HEAD TUTOR: SALLY PEACOCK 43 VJSC 2009 MIRRORS The “OPTICS” of EUCLID was a treatise on perspective, the geometrical principles of vision. Before beginning our adventure of discovering the physics of OPTICS, let us look at some of the results which may help us. 1. “Equal magnitudes situated at unequal distances from the eye appear unequal and the nearer always appears larger” Do you agree with that statement? ............................................................................................................................ 2. Parallax Hold a pencil vertically at arm’s length. In your other hand, hold a second pencil about 15cm closer than the first. Without moving the pencils, look at them while you move your head from side to side. Which way does the nearer pencil appear to move with respect to the one behind it when you move your head to the left? ............................................................................................................................ Now move the pencils closer together and observe the apparent relative motion between them as you move your head. Where must the pencils be if there is to be no apparent relative motion, that is, NO PARALLAX between them? ............................................................................................................................ 44 VJSC 2009 Experiment 1 AIM: Using the method of parallax, locate images in a plane mirror • Support the plane mirror vertical on table. Stand an object about 10cm in front of the mirror. Where do you think the image of the object is? ............................................................................................................................ Move your head from side to side while looking at the object and the image. Is the image in front of, at the same place as, or behind the real object? ............................................................................................................................ ............................................................................................................................ • What part of the mirror reflects the object? ............................................................................................................................ • Locate the position of the image of the object by moving a second object around until there is no parallax between it and the image of the first object. Mark the position of the object, its image and the position of the reflecting surface of the mirror of the paper. DO NOT MOVE THE MIRROR OR OBJECTS! • Now repeat this experiment for two other objects. Remove the mirror and measure the distances from the objects to the reflecting surface and complete the following table. Type of object Distance of object Distance of image pin from mirror pin from mirror Object 1: Object 2 Object 3 How do the distances of the image and object from the reflecting surface compare? ........................................................................................................................... 45 VJSC 2009 Experiment 2 AIM: (a) (b) To locate the position of an object by drawing rays which show the direction in which light travels to it from our eye. Use the method of (a) to locate the image of an object in a plane mirror • Place a new sheet of paper on the table, under the mirror. Draw a line on the paper to mark the location of the mirror • Stick a button onto the piece of paper. This will be the object button. • Establish the direction in which light comes to your eye from the object button by sticking 2 additional buttons into the paper along the line of sight • Your eye should be at arm’s length from the buttons as you stick them in place so that all three buttons will be in clear focus simultaneously. • Look at the object button from several widely different directions and, with more buttons, mark the new lines of sight to the object button. • Use a pencil to mark the paper through the centre of the buttons. • Remove the mirror, then, with a ruler draw a line through each set of line of sight to the mirror. Using a dashed line, continue the lines beyond the mirror. • Where do these lines intersect ........................................................................................................................... • THIS POINT IS THE IMAGE • Measure the distance of the image from the mirror and the distance from the object to the mirror. Distance from object to mirror: .......................................................................... Distance from image to mirror:.......................................................................... • Do these measurements agree with those from experiment 1? ........................................................................................................................... ........................................................................................................................... 46 VJSC 2009 • Repeat this experiment on a new piece of paper, but this time, when you draw the lines-of-sight draw them to the mirror, but not past the mirror. • Where the lines meet the mirror, draw a line back to the original object button. What do you conclude about the angles formed between the mirror surface and the light paths? ........................................................................................................................... ........................................................................................................................... • Draw a line perpendicular to the mirror from the point where an incident ray meets the reflecting surface. This line is called the normal to the mirror. What part of the mirror reflects the light? ........................................................................................................................... The angle between the incident ray and the normal is called the angle of incidence. What do you think would be called the angle of reflection? ........................................................................................................................... • Measure the angle of incidence and the angle of reflection • Enter your results in the table below. • Repeat the experiment for 4 different angles of incidence Experiment Angle of incidence Angle of reflection 1 2 3 4 What can you conclude from your table of results? ........................................................................................................................... ........................................................................................................................... Can you explain why you can see the sky in a puddle, or in a lake? ............................................................ ............................................................ 47 VJSC 2009 The Greeks in the 4th century BC had discovered that: 1) The angle of incidence = the angle of reflection (i.e. = , in the picture above) 2) The image is as far behind the mirror as the object is in front. Do your results agree with these? 48 VJSC 2009 Some exercises What do you think will happen in these situations? Draw the rest of the path of light. LIGHT MIRROR MIRROR BLUE MIRROR RED LIGHT MIRROR 49 VJSC 2009 More exercises What do reflections of letters look like? 1. On a new piece of paper under the mirror write the following letters. Draw the image of the letter in the space in the following table. A B G N 2. On a separate piece of paper write the following letters, then turn the sheet towards the mirror. Draw the image of the letter in the space in the following table A B G N 50 VJSC 2009 3. On a sheet of transparent paper, write the following letters, then turn the sheet towards the mirror. Draw the image of the letter in the space in the following table: A B G N What do you notice about the orientation of the images? ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... What do you notice about the size of the image relative to the size of the object? ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... 51 VJSC 2009 Draw a picture of how the light rays travel to reach your eyes, for each of the three exercises. In your sketch make sure you include: • Where your eyes were • Where the mirror was • Where the letter was • Is your picture drawn from above? Or from the side? Exercise 1 Looking down at the mirror, and the page Exercise 2 Reading letters on a piece of paper Exercise 3 Reading letters on a transparent sheet Questions: 52 VJSC 2009 Are there any letters that look the same in mirror writing? Write them down ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... How would you write: “Seeing is believing” in mirror writing? ........................................................................................................................... Can you write a secret message to your friend in mirror writing? ........................................................................................................................... ........................................................................................................................... How might you read a secret message written in mirror writing? ........................................................................................................................... ........................................................................................................................... Emergency vehicles such as ambulances are often labelled on the front hood with mirror writing. Explain why this is so. ........................................................................................................................... ........................................................................................................................... Draw the lines of sight to the two ends of the arrow in the following drawing. Use a dashed line to show the line of sight to the image beyond the mirror. IMAGE OF MIRROR ARROW EY 53 VJSC 2009 Harder Questions: If you walk across a room at 1m/s towards a plane mirror, with what speed does your image move? Give reasons for your answer. ........................................................................................................................... ........................................................................................................................... With what speed does your image approach you? ........................................................................................................................... ........................................................................................................................... A piece of white paper reflects a lot of light, yet you cannot see your own image in the paper. Explain. ........................................................................................................................... ........................................................................................................................... 54 VJSC 2009 Experiment 3 AIM: To investigate of images of images, i.e. to answer the question – “can mirrors produce more than one image of an object?” • Set up 2 mirrors end to end along one of the axes of a graduated circle, and place an object in front of the join of the mirrors – say 4cm from the mirror. How many images do you see? ............................................................................................................................ • Decrease the angle between the mirrors by rotating both mirrors about the join A, while keeping your eye directly in front of A. How many images can you see when the angle between the mirrors is 120°? ............................................................................................................................ How many images can you see when the angle between the mirrors is 90°? ............................................................................................................................ How many images can you see when the angle between the mirrors is 45°? ............................................................................................................................ What about other angles of the mirror? Angle 120 90 Number of images 45 Can you find any relation between these numbers? ............................................................................................................................ Can you predict the angle when these will be: 1) 11 images? ........................................... 2) 15 images? ........................................... 55 VJSC 2009 Some more exercises Look in a mirror and wave to yourself. Which hand are you waving with? Which hand is your image waving with? ........................................................................................................................... ........................................................................................................................... Put two mirrors at right angles to each other. Look into the corner of the mirror. You should see your reflection. Wave at your reflection. Which hand is your image waving with? ............................................................................................................................ ............................................................................................................................ Draw in the lines of sight in the sketch to see what is happening. MIRROR EYE MIRROR 56 VJSC 2009 LESSON 5 KIDNEY DISSECTION HEAD TUTOR: TRAN LAM 57 VJSC 2009 The Urinary System The principal function of the urinary system is to maintain the volume and composition of body fluids within normal limits. It keeps chemicals, such as potassium and sodium, and water in balance by regulating the amount that is excreted in urine. The urinary system plays a major role in excretion, the removal of waste from the body, in the form of urine The body takes nutrients from food and converts them to energy through a process known as cellular metabolism. This results in the production of waste that is left behind in the intestines and in the blood. Waste carried in the blood, called urea, is produced when foods containing protein, such as meat, poultry, and certain vegetables are broken down in the body. Urea is carried in the bloodstream to the kidneys. Although the urinary system has a major role in excretion, other organs contribute to the excretory function. Lungs Skin Liver & intestines Removes bile pigments that result from the destruction of haemoglobin. Haemoglobin is found in red blood cells, responsible for carrying and transporting oxygen in the bloodstream. The major task of excretion still belongs to the urinary system. If it fails the other organs cannot take over and compensate adequately. Other functions of the urinary system include: - Regulating the concentration of various electrolytes in the body fluids and maintaining normal pH (the acidity) of blood Controls red blood cell production by releasing a specific hormone called erythropoietin Maintains normal blood pressure by releasing a specific enzyme called renin 58 VJSC 2009 The urinary system consists of the paired kidneys, the paired ureters, the bladder and the urethra. What is the function of the following organs in the urinary system? Kidney: ___________________________________________________________________ ___________________________________________________________________________ Ureter: ____________________________________________________________________ ___________________________________________________________________________ Bladder: ___________________________________________________________________ ___________________________________________________________________________ Urethra: ____________________________________________________________________ ___________________________________________________________________________ Normal urine is sterile. It contains fluids, salts and waste products, but it is free of bacteria, viruses and fungi. 59 VJSC 2009 The kidney The kidneys are located at the back of the abdominal cavity, one on either side of the spine. The RIGHT kidney sits below the diaphragm, behind the liver while the LEFT is below the diaphragm, behind the spleen. Due to the arrangement of the large liver the right kidney sits slightly lower than the left. The kidneys are purple/brown in colour and are often described to be BEAN-shaped WHAT HAPPENS INSIDE THE KIDNEY? Waste transported via the bloodstream enters the kidney through the renal artery which branches off into smaller blood vessels, called arterioles. The kidney consists of millions of tiny filtering units, called nephrons. Each nephron is made up of a very small filtering network of capillaries called the glomerulus, which is surrounded by the Bowman’s capsule attached to the renal tubule. Water and waste products are separated from the blood at the glomerulus and flows into the tubules. The bulk of water re-absorption takes place in the Loop of Henle (part of the renal tubule) and the wastes are concentrated into urine. Have you ever noticed the colour and smell of your own urine? Discuss the difference between concentrated and dilute urine. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ 60 VJSC 2009 NEPHRON The organs of the body all work together to maintain homeostasis. This is changing its internal environment to maintain a stable, constant condition for proper function. HOW IMPORTANT ARE THEY? The kidneys are the most important organs in the urinary system, involved in excreting waste. If one fails the other functioning kidney can still do the work of two kidneys. However, when both kidneys fail, wastes and fluids accumulate in your body and you need dialysis treatments (to clean your blood either by machine or in your abdomen), or a kidney transplant. No other system or organ can replace the job of the kidneys. The kidney normally makes one to two litres of urine every day depending on how much you drink. The normal kidney has the ability to greatly increase its workload. If one kidney is lost, the other kidney can enlarge and do the work of two. 61 VJSC 2009 LABEL THE KIDNEY MEDULLA ARTERY RENAL VEIN CORTEX RENAL RENAL PELVIS URETER RENAL CAPSULE 62 VJSC 2009 ACROSS 1. The process of breaking down nutrients 2. Normal urine is __________ 3. Tubule where urine exits the body 4. Organ that stores urine 5. Tiny filtering units in the kidney 6. Tubule where most water re-absorption occurs 7. To keep the body at a balance (stable & constant) DOWN 1. Less water, more waste is __________ urine 3. Waste carried in blood 4. --- capsule 8. Region that consists of 6 across 9. Tubule in which urine from the kidney travels to the bladder 10. Major role of the urinary system 11. Common word: _ _ _ _ _ artery supplies blood to kidney _ _ _ _ _ tubule 12. Small network of capillaries in the kidney that filters the blood 1 9 8 10 2 11 5 3 4 12 6 7 63 VJSC 2009 64 VJSC 2009 LESSON 6 FIRST AID HEAD TUTOR: CHARLOTTE ROBINSON 65 VJSC 2009 Your guide to looking cool and saving lives! 66 VJSC 2009 Note for Parents/Carers We will be using the following ingredients and materials in this class: • • • • • • • • • • • • • Plain Flour Cream of Tatar Cooking Oil Salt Food Colouring Liquid latex Make up palette – eyeshadow/blush Parisian Browning Essence Vaseline Glucose Syrup Sorbolene Latex gloves Alcohol wipes Please make the Head Tutor aware if your child has any Allergies, especially to the materials listed above. 67 VJSC 2009 Always check for Danger to: • Yourself • Bystanders • Casualty Check to see if someone is conscious or awake by • Squeezing the shoulders • Asking Can you hear me? Open your eyes. What is your name? If they don’t respond, call 000 or 112. If they are unconscious, leave them on their back. Make sure the unconscious person has a clear and open Airway by • Opening the mouth • Checking to see if there are objects in there • Scooping/Scraping any objects out of their mouth using two fingers 68 VJSC 2009 Check to see if a person is breathing by • Looking • Listening • Feeling If a person is breathing, roll them on their side into the Recovery position. If a person is not breathing check for signs of life (next step). Check for signs of life from the casualty e.g. breathing, movement, eye opening, colour of lips. If the casualty is not breathing, commence CPR: • Give 30 compressions • And 2 breaths If you have access to a defibrillator, attach pads to the casualty and follow the prompts of the machine. 69 VJSC 2009 Blood transports oxygen and nutrients to all the organs and muscles of the body via blood vessels. Your skin is your first line of defence to protect your body from infection and your muscles, organs and blood vessels from damage. An object damaging the skin may cause an open wound which will bleed. There are different types of open wounds such as: • Abrasion or a scrape on the skin by a hard surface • Incision or cut of the skin by a sharp object e.g. knife • Laceration which is like a cut, but is made by something with a rough surface e.g. barbed wire, teeth • Puncture which is like a hole made by something sticking into the skin • Tear when an object rips some of the skin But no matter the cause or type of open wound, the treatment for each wound follows the same principles which are: 1. Control the bleeding 2. Apply pressure to the wound to restrict blood flow to the area 3. Elevate the injured part to slow blood flow to the area 4. Maintain pressure on the wound 5. Minimise shock 6. Minimise the risk of infection by using protective gear and clean dressings and utensils and cleaning the wound 7. Consider medical aid What is Shock? When blood doesn’t circulate properly, not enough oxygen gets to the vital organs and tissues which can cause them to shut down. Shock can be a life threatening condition and must be treated seriously and promptly. It can be caused by: • Bleeding • Pain • Heart failure • Trauma • Vomiting and diarrhoea • Infections • Burns • Allergic reactions Signs and symptoms include: • Pale face • Cold, clammy skin • Faintness or dizziness • Nausea • Weak and rapid pulse • Anxiety • Shallow, fast breathing • Drowsiness, confusion or unconsciousness • Blue around the lips and fingers 70 VJSC 2009 Treating Shock 1. Follow DRABC 2. Reassure the casualty 3. Call 000 4. Raise the casualty’s legs (unless injured) above the level of the heart 5. Cover the casualty with a blanket to keep warm 6. Monitor pulse and breathing Checking for Circulation To make sure the area around a wound is receiving enough blood, check for the circulation by: • Checking the skin colour – if it is too pale, circulation may be impaired • Check the skin temperature - if it is too cold, circulation may be impaired • Check for capillary refill by lightly pressing fingernails of toenails. If the colour does not return to the finger or toe within 3 seconds, circulation may be impaired. Treating a laceration/Incision 1. Follow DRABCD 2. Lie or sit the casualty down 3. Put on gloves and protective eyewear 4. Remove or cut clothing to expose the wound 5. Apply firm direct pressure to the wound 6. Clean the wound with saline and gauze 7. Apply a non-stick dressing to the wound and hold in place with a bandage 8. Check for circulation to the limb 9. Elevate the wound 10.Treat for shock if needed 11. If bleeding comes through the dressing/pad, add another dressing and re-bandage. 12. If bleeding comes through the second pad, replace the second pad only and re-bandage 13. If bleeding continues or if the casualty is in shock, call 000. Page 71 of 101 VJSC 2009 Burns are injuries to the skin and underlying tissue caused by heat, extreme cold, friction, chemicals, sun etc. Burns are classified by their causes, and each type is treated slightly differently. But the general principles for treating a burn are: 1. Follow DRABCD 2. Cool the burnt area 3. Cover the burnt are with non-adherent dressing 4. Prevent infection by covering the burn wound 5. Minimise shock by reassurance When treating burns • DO NOT apply lotions, ointments or oily dressings • DO NOT prick or break blisters • DO NOT give alcohol • DO NOT overcool the casualty • DO NOT use towels, cottonwool or adhesive dressings on wound • DO NOT remove clothing stuck to burnt area If a person’s clothing is on fire, remember to Stop the casualty from running around Drop the casualty to the ground and wrap in a blanket Roll the casualty along the ground until the flames are smothered Thermal Burns Thermal burns are caused by contact with heat e.g. flames, hot objects, scalding by steam or liquid or burning by friction. Treating a thermal burn 1. Follow DRABCD 2. Extinguish burning clothing or remove scalded clothing 3. Hold burnt area under cold, running water for 20 mins 4. Cover burn with a non-adherent burns dressing 5. Seek medical aid Page 72 of 101 VJSC 2009 Fake Skin (Play-dough) Recipe Ingredients: • 2 cups plain flour • 4tbs McKenzie’s Cream of Tartar • 2tbs cooking oil • 1 cup of salt • Food colouring (red and Parisian browning essence) • 2 cups of water Method: Mix the ingredients in a saucepan Stir over medium heat for 3-5 minutes or until the mixture congeals. Transfer mixture to plastic board and knead in food colouring until desired skin tone is reached. (Note: You generally need more browning essence than red food colouring. Add colouring one drop at a time to ensure you don’t go to dark or red.) Fake Blood Recipe Ingredients: • Glucose Syrup • Food Colouring (Red, Blue, Yellow) Method: Add food colouring one drop at a time to glucose syrup and stir, until desired colour of blood is reached. Page 73 of 101 VJSC 2009 Page 74 of 101 VJSC 2009 LESSON 7 VISCOSITY & DENSITY HEAD TUTOR: MURAT KEKIC Page 75 of 101 VJSC 2009 Viscosity and Density Background Viscosity In general terms, viscosity is the measure of how thick a liquid is. We can think of water as being “thin”, so therefore it has a low viscosity. On the other hand we think of oil as being “thick” and therefore it has a higher viscosity than water. In more technical terms, viscosity measures the amount of internal friction (or resistance to flow/stress) that a liquid has. You can try for yourself at home; if you pour water out of a glass it pours out easily, but if you pour oil it pours a lot slower. All real fluids have some resistance to stress (or an internal friction). The viscosity of a liquid depends on a number of things. The main factors are how big the molecules, how quickly they move are and how strong the bonds are between the molecules. The temperature of the liquid will also influence its viscosity. Density Density is the measure of mass per unit of volume. In chemistry, we often compare the density of many substances to water. For example, if you had a glass marble and put it in a jar of water it would sink. However, if you had a piece of foam that was exactly the same size of the marble and put it in the jar of water it would float. Therefore, the density of the marble is higher than the density of the foam. Experiments Today we will be doing 2 experiments. The first experiment will help us learn about viscosity and the second will help us learn about density. Experiment 1 Viscosity Which solution is the “slowest”? Materials Gloves Aprons Measuring cylinders Stop watch Glycerol Water Empty bottles Grapes Page 76 of 101 VJSC 2009 Method 1. Please put on your disposable apron and gloves. 2. Take the four 250ml measuring cylinders and label them as 0%, 10%, 20% and 30% 3. Using the empty bottles, you need to mix up 4 different solutions of glycerol and water – 0% glycerol, 10% glycerol, 20% glycerol and 30%glycerol (you will be given directions on how to do this) 4. Pour the solutions you have mixed up into the correctly labeled measuring cylinder. 5. One student holds the stopwatch and the other holds the grape. 6. Carefully place the grape near the top of the solution labeled 0%. When you let go of the grape you yell out go and the student holding the stopwatch starts timing. Stop the timer when the grape hits the bottom of the cylinder. 7. Write down the time in the table provided. 8. Now swap with your partner and repeat the measurement. 9. Repeat until you have completed all the solutions. 10. Now, you will plot the time versus % glycerol on the graph paper provided. The percentage of glycerol is on one axis and the time taken is on the other. % Glycerol 0 Time 1 Time 2 Average 10 20 30 Questions: Which solution was slowest? _________________________________________________________________________________ Why do you think this one is the slowest? _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ Page 77 of 101 VJSC 2009 Experiment 2 Density Can you make an egg float in water? Materials Beaker Water Salt Spoon Electronic balance Method 1. Put about 200 mL of water in your beaker 2. Weigh your beaker and record the weight Weight = 3. Place the egg into the water What happens? 4. Add salt to the water one spoon at a time – after you add each spoon stir until the salt dissolves and then place the egg in the water to see if it floats. Keep adding salt until the egg floats. How many spoons of salt did you add? What does your beaker weigh now (without the egg)? Weight = Page 78 of 101 VJSC 2009 Page 79 of 101 VJSC 2009 Page 80 of 101 VJSC 2009 LESSON 8 SLIME HEAD TUTOR: ANKUR CHAUDARY Page 81 of 101 VJSC 2009 Slimed! What is a liquid? To understand what a liquid is, we have to understand how scientists classify matter. Objects can be classified into: 1. Solids Properties of Solids: ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________ (http://www.mosaicpersonnel.com.au/blockstack.jpg) 2. Liquids Properties of Liquids: _________________________________________ _________________________________________ _________________________________________ _________________________________________ _________________________________________ (http://www.maplewoodplumbing.com/images/water.jpg) 3. Gases Properties of Gases: ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ (http://www.steamline.com/images/steam%20kettle.jpg) Page 82 of 101 VJSC 2009 Properties of matter (http://www.grc.nasa.gov/WWW/K-12/airplane/state.html) Solids: • • • Liquids: • • Gases: stay in a fixed volume and shape (because bonds between atoms are very strong, keeping the shape rigid), unless forced or broken are not easily squashed (becase there is little space between atoms) do not flow (as atoms cannot slide past one another) • flow into the shape of a container (as atoms can slide past one another) are not easily squashed (there is little space between atoms, but the bonds are not as strong as the bonds between atoms in a solid) flow easily • • • fill the container they are in (as the atoms can freely move) very easily squashed (there is a lot of space between atoms) flow very easily (very little force is needed to move free atoms) There are also some specialised classifications of matter such as: Plasma Bose-Einstein condensate (http://news.bbc.co.uk/olmedia/655000/ images/_655518_bose300.jpg) Fermionic condensate (http://jilawww.colorado.edu/~jin/publications/images/ 3Dview-1.jpg) (http://www.astronomycafe.net/qadir/ask/ plasmaBall.jpg) These will not be covered today, but you can ask the head tutors about them. Page 83 of 101 VJSC 2009 Non-newtonian liquids Today’s investigation will be into liquids that sometime don’t behave normally. The liquid that is usually the standard for ‘normal’ is water, so all liquids we observe today will be compared to water. In Murat’s lesson, you will learn about viscousity, which is how sticky, or dense some liquids can be – such as tomato sauce, blood, honey and motor oils. A non-newtonian liquid is defined as a liquid that doesn’t have the same viscousity all the time Prepare 2 liquids and consider their properties: #Liquid 1 Materials: • Corn starch • Water • Food colouring This is a messy experiment, so remember to wear your aprons and eye protection Process: 1. Pour a cup of corn starch into a bowl 2. Mix in water until it forms a paste (between ½ and 2 cups of water) 3. Mix in a couple of drops of food colouring Note the properties of this liquid: Does the liquid flow? If the liquid is pushed or poked, does it remain a liquid? Can the liquid be gathered into your hand? ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ #Liquid 2 Materials: • White glue • Borax (sodium borate) in water • Food colouring Borax is a mild acid, so remember to wash your hands before leaving the lesson Process: 1. Mix the white glue and borax water in equal amounts 2. Knead the mixture till it sets, adding a couple of drops of food colouring before it sets completely Note how this liquid behaves, as you try to stir it, stretch it, squash it. These two liquids are classified as such because: • they both flow • they cannot be squashed easily • bonds between particles allow them to slide between each other Enjoy playing with your sample of silly putty (which is also a liquid), and keep investigating strange liquids! Page 84 of 101 VJSC 2009 LESSON 9 SCIENCE IN THE KITCHEN HEAD TUTOR: LIBBY CHALMERS Page 85 of 101 VJSC 2009 Did you know that you can be a scientist in your own home? Lots of liquids in your kitchen can have very interesting affects when added together. All substances can be categorized as acidic, neutral or basic. The table below shows some properties of each. ACID NEUTRAL BASE Taste sour Distilled water Taste bitter pH 0 - 7 pH 7 pH 7-14 when acids and bases Turns litmus paper are mixed together, blue the product is neutral When added to water, When added to water, it separates into it separates into + hydroxide atoms hydrogen atoms (H ) (OH-) Turns litmus paper red Page 86 of 101 VJSC 2009 pH is a measure of how acidic or basic the substance is. It is measured on a scale from 0 to 14. Below are some examples of common household substances on a pH scale. Experiment 1: Volcano We will be starting with an acid-base reaction that will involve creating a volcano. Hypothesis: ________________________________________________________ _______________________________ ________________________________________________________ _______________________________ (Note: If you were at last year’s Science Challenge, you might remember how we added detergent to water in order to make bubbles, and we will be doing similar things today) Page 87 of 101 VJSC 2009 Procedure: 1. Put some water, baking soda and a little bit of detergent in a bottle. 2. Add some vinegar 3. Write down what you see Observations: _______________________________ _______________________________ _______________________________ _______________________________ _______________________________ _______________________________ _______________________________ Why? ________________________________________________________ ________________________________________________________ ________________________________________________________ Page 88 of 101 VJSC 2009 Experiment 2: Cabbage Juice Did you know that veggies can be used in the science lab? Here we use cabbage to measure the pH levels of some common liquids. Ingredients: Red Cabbage Grater Water Cups Acidic and Basic liquids (eg. tap water, fruit juice, vinegar, bicarbonate of soda, detergent) Procedure: 1. Grate the red cabbage (you don't need a lot of it) 2. Add water and the cabbage to a bowl 3. Squish the grated cabbage until you get some juice out of it. 4. Extract the juice (no pieces please!) into multiple cups 5. Put a few drops of vinegar into a cup. 6. Observe and write down the colour in the space below 7. Repeat steps 5 and 6 with different liquids and fresh cups of cabbage juice. Page 89 of 101 VJSC 2009 Observations: LIQUID COLOUR pH ACID or BASE Tap water Fruit juice vinegar Bicarbonate of soda detergent Page 90 of 101 VJSC 2009 Experiment 3: Diet Coke and Mentos Mentos Last but certainly not least – This one is my favourite!! Aim: To observe the reaction when Mentos is dropped in Diet Coke. Hypothesis: ________________________________________________________ ________________________________________________________ Procedure: 1. Open packet of mentos 2. Open bottle of coke 3. Drop a few mentos into the bottle (not too many!) 4. Observe Page 91 of 101 VJSC 2009 Observations: + = Why? ________________________________________________________ ________________________________________________________ ________________________________________________________ Page 92 of 101 VJSC 2009 Word Search N E U T R A L I S E R S W J O Q T P E J C W L L O R N J V V R N V E B K I U N B Q T V R I M E X U B Q L A D B A S E N N H M T F U M C E A C N Q H U E M I G I O L M G G Y U E D S G X R D A O T N A L L L H U I A A E H V P J L B Z F E I N S R K P O S E L B B U B L R Y E S A X S H T I F A G Y E B V H E K E V O E V O C W T U M A T H G M O H U O D R T K Z G S O G N H B G P R V I Q T U D D P B HYPOTHESIS BITTER LIQUID BUBBLES SOUR EXPERIMENT BASE VOLCANO CABBAGE VINEGAR ACID NEUTRALISE M B G H W M B Y C L F S N Y J F Y P P Z L Z L R A J Q D H Z Page 93 of 101 VJSC 2009 Page 94 of 101 VJSC 2009 LESSON 10 MOLYMODS HEAD TUTOR: NICHOLAS GAD Page 95 of 101 VJSC 2009 Chemistry Chemistry is the branch of the natural sciences dealing with the composition of substances, their properties and reactions. Atom The atom is the smallest particle that can exist on its own under normal conditions. Parts of the Atom: 1) ____________________ 2) ____________________ 3) ____________________ 4) ____________________ (Electron, Neutron, Nucleus, Proton) Elements There are 88 naturally occurring elements, each having a different number of protons. Each element has different physical and chemical properties and is the smallest individual substance that any substance can be reduced to. Top ten most important elements needed for life (left to right then down) H( )– O( )– C( )– N( )– P( )– Ca ( )– S( )– Na ( K( )– Cl ( )– )– Other important elements He ( 2 ) – Helium Ag ( )– Au ( Cu ( )– )– Page 96 of 101 VJSC 2009 Compounds A compound is made when two or more elements bind together to form a new substance with different properties to the two original elements. Molecule or covalent compound – Molecules are usually formed from two or more non-metal elements or compounds. The bonds of a covalent compound are usually strong as electrons are shared between atoms. Gases and liquids are mainly covalent compounds and most will not conduct electricity. Salt or ionic compound – Salts are usually formed from a metal and a non-metal element or charged compound. The bonds of salts are usually weak as the metal transfers its electron to the non-metal part. Most salts are water soluble, and form ions (charged particles) in water allowing electricity to pass through. Mixtures/alloys – A mixture is the combination of different molecules and salts. There is no binding between the substances, and they can usually be separate by purely physical means. An alloy is a mixture of two or more metals. When similar substances are mixed, the mixture usually has properties that are an average of the various substances. Organic and inorganic chemistry There are two classes of substances, organic and inorganic. Likewise most chemistry work divides into these two classes. Organic – Carbon is the only element that allows the formation of extremely long chains. As this allows an enormous number of different carbon-based substances to be made, carbon has its own category in chemistry. Organic compounds must have carbon in them and nearly always have hydrogen as well. Inorganic – Basically all other substances that do not have carbon in them. Inorganic substances often have metals in them and usually salts are inorganic. H H H O + H H H Na Cl H H H H O H H H H H H H H H H H O F H O F O H + F H N H F H O H H O H H H O Are these compounds organic or inorganic? Super Glue The general name for this group of compounds is cyanoacrylate. A nuclearphile (usually the hydroxide ion from water) attacks the third carbon of the compound, pulling an electron from Page 97 of 101 VJSC 2009 the second carbon. This then causes a chain reaction, forming a polymer from the cyanoacrylate molecules. It is this polymerisation that gives superglue its strength. OH- N H O O N N O O O O O (1) (2) N H N N - O O O O O O O (3) Making the molecule Carbon – black atom Oxygen – red atom Nitrogen – blue atom Hydrogen – white atom Single bond – white link Double/triple bond – grey links Page 98 of 101 VJSC 2009 Page 99 of 101 VJSC 2009 Page 100 of 101 VJSC 2009 FRIENDS Name Email Phone Page 101 of 101