Science 9 Final Exam Review KEY Safety and Chemistry 1. Explain the particle model of matter and how temperature affects matter. -matter is made up of small particles -space between particles changes depending on temperature -particles are always moving -particles are attracted to one another/strength depends on types of particles TEMPERATURE provides KINETIC ENERGY to particles meaning the move faster and further away from one another 2. Draw and explain each of the WHMIS symbols. Dangerous Container (outside) Dangerous Product (inside) 3. List and explain the quantitative properties of matter. Quantitative: means physical properties than can be measured with NUMBERS 4. Explain what is meant by the term pure substance. Pure Substance: made up only ONE kind of matter. There are 2 KINDS: 1. ELEMENT 2: COMPOUND (2 or more elements) 5. List the three subatomic particles; be sure to explain where they are located and their charge. 6. Explain the difference between families and periods. Noble Gases Alkaline Earth Metals Periods: HORIZONTAL ROWS Families: VERTICAL COLUMNS (transition and rare-earth metal families are made up of multiple columns ) 7. List and locate the four families on the periodic table. *see above diagram Alkali Metals: highly reactive with oxygen and water, lose 1 electron Alkaline Earth Metals: not as reactive as alkali metals but will burn brightly, lose 2 electrons Halogens: highly reactive, poisonous, need ONE extra electron for full valence shell Noble Gases: usually do not react, have a FULL valence shell 8. Describe the properties of metals, non-metals and metalloids. 9. Explain how the periodic table is organized. 10. Explain the difference between an atom and an ion. Atoms: HAVE NOT reacted, have NO charge Ions: : HAVE reacted, HAVE either a +/- charge, 11. What is the electron arrangement for an atom? Atoms want to have full valence shells (if possible) and react by either GAINING or LOSING electrons to fix their outer/VALENCE shell 12. Using a Bohr diagram, draw an atom and ion of the element aluminum. ATOM: no charge unfilled valance ION: +3 charge/lost three electrons filled valence 13. Explain what is meant by the term valence electrons. Valence: outer shell electrons that are either LOST or GAINED when an atom REACTS to become an ION 14. Explain the difference between ionic and covalent bonds. 15. Write the correct formula for the following compounds: a. Silver Nitride b. Aluminum Phosphide c. Chromium II chloride d. Copper I Nitride e. Lithium dichromate f. Manganese IV sulphate g. Aluminum hydroxide 16. Write the name for the following compounds: a. Na2O b. Ag3N c. CrBr3 d. Fe2O3 e. Mg3(PO4)2 f. (NH4)3P g. NaCH3COO 17. What two things can you determine from a chemical formula? -The MINIMUM number of each elements needed to make the compound -Whether the compound is ionic or covalent. 18. Explain the difference between a physical and chemical change. PHYSICAL: change in state or dissociation of a compound into ions. NO new products made CHEMICAL: a reaction where NEW products are made. It is not usually reversible Reproduction 1. Explain the relationship between DNA, genes and chromosomes. -DNA is very long double-chained strands of genetic material. -Genes are SHORT sections along the DNA chain that code for either RNA messages or PROTEINS -Chromosomes are one double stranded DNA chain tightly wound up and held by HISTONE proteins mainly forming X-shaped structures 2. What is a mutagen and provide an example. Mutagen is something that causes a change to the GENETIC CODE in DNA. Examples are: cigarette smoke, X-rays, UV-light, pesticides, pollutants, some household cleaners, food additives 3. What is meant by the term genetic code? Genetic code refers to the SEQUENCE of base pairs (A,T,C,G) found in a chromosome or DNA strand 4. Draw and label an animal cell and give a brief explanation for each of the organelles. Cell membrane Layer that surrounds cells, controls what enters and leaves Cytoplasm Jelly like substance, houses organelles Ribosome Involved in protein production Golgi Body Sorts and packages proteins for transport Nucleus Contains nuclear information about cell and important proteins Mitochondria Powerhouse that is responsible for energy production of a cell 5. Explain the difference between neutral, positive and negative mutations. Neutral: Mutation in code that doesn’t alter the function of any proteins made Positive: Mutations that creates a change that POSITIVE for the organism and offers it an advantage in its CURRENT ENVIRONMENT. *remember: if you change the environment the effect may not be positive anymore Negative: Mutation that affects the functioning of a protein leading to harm or a negative effect on an organism. *remember: a negative mutation may not always stay negative if the environment changes 6. Explain what is meant by complementary base pairing in reference to DNA? It means there are base pairs that always connect: A with T, and C with G 7. List and describe the different types of proteins produced in the human body. Structural: make up the structure of the cell Enzymes: are necessary for biochemical reactions to happen in a cell (amylase in saliva is an example) Hormones: are chemical messengers that control functions (insulin is an example) 8. Briefly explain gene therapy. Gene therapy usually involve using a harmless virus that is engineered to contain a gene that is not working in a human. The geneticist will then try to target certain types of cell with the virus where the virus DNA containing the added gene will be inserted into the cells not working properly. The cells now will have the working gene and make the protein. 9. List and briefly describe the different types of asexual reproduction. Binary Fission: In bacteria where chromosome is replicated and each daughter is identical (very quick) Budding: Found in sponges and hydras, section of an organism can undergo mitosis and grow into a new organism ad either stay attach or break off Fragmentation: Found in some plants and animals (sea stars), where pieces of an organism can grow into new organisms through mitosis 10. Describe the cell cycle. DNA is replicated 11. Draw and describe what occurs at each stage of mitosis. 12. What is the purpose of therapeutic cloning? The purpose of this therapy is to design ways to start using cloned cells to act as STEM CELLS that can become many different cell types. This creates a flexible starting cell that could be used to grow specialized tissues and organs for transplant. The idea here is that if you could find a way to grow organs from your OWN cells, you could then transplant them in case of a disease or injury without your body rejecting the transplant. Remember, right now transplant patients receive organs form OTHER people, and their immune system sees the transplants as foreign and attacks the new organ. 13. List and describe the parts of a flower. 14. What is the advantage of sexual reproduction? It provides a way of shuffling genes during meiosis (when gametes/egg and sperm are made). This means that each resulting egg or sperm is different. This increases VARIABILITY in a population of organisms. Variation is important because it improves survival because some organisms will have an advantage over others in an environment. 15. What types of cells go through meiosis? Reproductive cells undergo meiosis to produce egg or sperm cells that have HALF the total number of chromosomes as regular cells. 16. What is the end product of meiosis? For sperm: there will be 4 different sperm cells with only half the regular number of chromosomes For eggs: there will be 1 egg, and 3 polar bodies (die) 17. Explain the difference between haploid and diploid. 18. What is meant by homologous chromosomes? 19. List and briefly describe the types of assisted reproductive technologies. Artificial Insemination: Sperm is collected and stored and later injected into a female In Vitro Fertilization: Sperm and an Egg cell are collected and the process of fertilization occurs in a lab. The resulting embryo is then implanted into the female. Gamete Intrafallopian Transfer: An egg and sperm cells are collected to create a mixture that is quickly injected into the woman’s fallopian tubes for fertilization to occur in the body. Intracytoplasmic Sperm Injection: Sperm cells and an egg are collected. In the lab, a single sperm cell is injected into an egg cell resulting in a zygote that is then implanted into the uterus of the woman. Electricity 1. What are the three laws of static charge? 1. Like charges will repel, but unlike charges will attract. 2. Electric charge is always conserved. It is something that is unable to be created or destroyed. 3. Electric charge is always quantized (means it can be measured). It has a discrete value, which does not change. 2. Explain the difference between an insulator and a conductor. Conductors: Allow for current to flow easily Insulators: Do not allow for current to flow very easily 3. Explain how current flows in a circuit. Current flows from the ANODE (-) to the CATHODE (+) but conventional current is from CATHODE to ANODE 4. What is the definition of current and what device measures current? Current: The amount of CHARGE passing in a conductor past a point very second. 1 AMP = 1 Coulomb = 6.24 x 1018 electrons 1 Second 1 second 5. What is the definition of potential difference? The difference in charge from one area to another. The potential means that as electrons flow they have the POTENTIAL to do work. Remember ONE VOLT = 1 Joule/C of charge. The larger the difference in charge or VOLTAGE the more energy that is available to be used for every charge moving in a circuit. In a circuit, the electrical energy is converted into light energy if a light is added to the circuit. 6. List the parts of a circuit and give a description of their purpose. Acts as a conductor for electron flow Stops the flow of current Allows current to flow Resists current and allows less current in a path Creates voltage or the driving force Multiple cells form a battery that creates more electric voltage or driving force for current Light source that is a resistor. Electrical energy is converted into LIGHT and HEAT energy 7. Describe Ohm’s Law. Means that as VOLTAGE INCREASES so does the CURRENT 8. Explain the difference between a dry and wet cell battery. Dry cells have a paste that creates a chemical reaction leading to the loss of electrons in the middle tube of the battery (CATHODE) and a gain of electrons in the outer area (CATHODE). This creates 2 ends of a battery A wet cell has a liquid region where one side is positive and the other side negative with + and - terminals attached to each region. 9. Explain what happens to voltage and current in a series and parallel circuit. Means that as VOLTAGE INCREASES so does th Series Battery: Voltage ADDS together Parallel Battery: Voltage stays the SAME *Notice that in the parallel battery that the battery life is 4 times longer 10ah vs 40ah SERIES Voltage drops at a RESISTOR ADD equal to TOTAL VOLTAGE Current is the same along the entire path PARALLEL Voltage drops at each resistor are EQUAL to the TOTAL VOLTAGE Current for each path ADDS to equal the TOTAL current *current is less for PATHS with BIGGER RESISTANCE 10. What happens to resistance in series or parallel circuits? SERIES PARALLEL Resistance decreases. In above example, it makes sense because HALF the current (of TOTAL) enters each path Resistance ADDS together to sum the TOTAL because there is ONE path 11. Draw a series circuit and parallel circuit; explain the difference. SERIES PARALLEL Series circuits have ONE path for current to flow. Parallel circuits have multiple paths for current to flow. 12. Write down the units for the following: resistance, current, voltage, power, energy, time Resistance: Ohms (Ω) Current: Amperes (A) Voltage: Volts (V) Power: Watts (W) Energy: Kilowatt Hour (kW●h) 13. A food processor requires 12A to operate. What is the power of the food processor when it is connected to a 120V circuit? 14. A 140W computer requires 10A to operate. What is the voltage produced by the computers battery pack? 15. A family receives an electric bill of $150.00 for month, and the power company charges 7 cents per kWh, how much energy did the family use? 16. If a washing machine consumes 3400W of power in 2 hours, how much energy has been used by the appliance? 17. An electric blender has a resistance of 165Ω and it is connected to a 120V power source. Calculate the current that flows through the motor.