Download File - Science 90 / Biology 20

SCIENCE 90
PHYSICAL SCIENCE
ATOMS AND ELEMENTS
CHEMISTRY UNIT OBJECTIVES
PART A – PHYSICAL VS CHEMICAL PROPERTIES OF COMMON
SUBSTANCES
1. Explore properties of matter, traditional uses of matter and physical and chemical properties of
matter.
2. Investigate common materials and substances and classify them according to their physical and
chemical properties.
3. Investigate changes in the properties of matter and identify indicators of chemical change.
4. Explore chemistry related science that exists in Saskatchewan.
PART B – HISTORICAL EXPLANATION OF STRUCTURE OF MATTER
5. Explore and describe atoms and elements (anatomy, molecules, compounds, charges, periodic
table info.)
6. Explore First Nations and Metis views on Matter.
7. Identify the development of theories on matter and construct models to identify the major historical
atomic models (Bohr, Dalton, Thomson, Rutherford, Bohr)
PART C – CLASSIFICATION OF SUBSTANCES (PERIODIC TABLE)
8. Differentiate between and be able to classify matter as either elements, compounds and mixtures.
9. Identify common elements and compare structure, graphic representations and examples of
diatomic molecules.
10. Write and interpret chemical symbols and formulas in common compounds.
11. Trace the historical development of the periodic table and explore its organization (rows, columns,
families, metals, non-metals, etc…)
12. Be able to determine atomic characteristics using information from the periodic table.
Objective 1: Matter and its Properties
Hunting the Elements - NOVA
What is “Matter”?
Anything in the universe which:
1-has a MASS (made up of ATOMS =
basic building block of matter)
2-has a VOLUME (takes up space)
Demo – Vacuum Jar
Which of the following can be considered matter?
Light
Air
Steam
Energy
Memories
Soundwaves
CO2
You
Olive Oil
Fire
Cell = basic building block of living things..
Atom = basic or simplest building
block of matter or stuff
(living or non-living).
http://www.wimp.com/seenatom/
jpg
QuickTime™ and a
decompressor
are needed to see this picture.
Molecule = more than one atom
attached together
Compound = more than one atom attached
together (MUST CONTAIN
DIFFERENT KINDS OF ATOMS)
QuickTime™ and a
decompressor
are needed to see this picture.
Molecule or Compound?
QuickTime™ and a
decompressor
are needed to see this picture.
Phases of Matter:
All matter exists in one of 4 phases as seen above:
-Energy and the Four States of Matter Solid Liquid Gas and Plasma YouTube
The Particle Theory of Matter
1. All matter is made up of small particles. (Particles can be atoms or
molecules.)
2. All particles of the same substance are identical.
3. The particles of matter are attracted to one another. (Attractions are
stronger if particles are closer together.)
4. The spaces between the particles are large compared to the particles
themselves.
5. The particles of matter are in constant motion.
When examining atoms and molecules we either
explore the:
Physical Properties = characteristics of a substance which
can be observed without changing the atomic makeup of
the substance
(freezing point, color, smell, density, etc…)
Water - > Ice --> Steam Periodoc table showing temp
for change of state
Chemical Properties = characteristics that describe a
substance as it is atomically changed. (combustion
temperature, reactivity with other chemicals, etc…)
Blue Paint + Yellow Paint = Green Paint
QuickTime™ and a
decompressor
are needed to see this picture.
Objective 2&3: Investigating Materials
according to their Physical and Chemical Properties
and Examine Indicators of Physical Change
Demo activity handout on Physical
properties through changes
Potassium iodide and lead nitrate – YouTube
Quick science: Iodine clock reaction – YouTube
Microwave Ivory Soap - Cool Science Experiment - YouTube
http://www.wimp.com/glasstechnologies/
The Chemistry of Snowflakes on
Devour.com
Chemical Change
• In a chemical change, the
original substance is changed
into one or more different
substances that have different
properties.
• Chemical changes always involve the
production of new substances.
• Chemical changes are difficult to reverse.
• Examples include burning, cooking and
rusting.
•
1.
2.
3.
4.
5.
How can you tell if a change is chemical or
physical?
There are many signs that can tell us.
Consider several clues before coming to a
conclusion.
A new color appears
Heat or light is given off
Bubbles of gas are formed
A solid material (called a precipitate) forms
in a liquid.
The change is difficult to reverse.
COLOR
HEAT&LIGHT
BUBBLES
PRECIPITATE
Quiz - Chem or Phys Change?
Bleach on colored paper
Iodine on a starchy cracker
64.
17.
Objective 4:
• Saskatchewan Chemist Jobs
• U of S Crop Chemist Breakthrough You
tube
• Careers in Chemistry - Youtube
Objective 5: Atoms and Elements
ATOM = The basic building block of all
matter.
MATTER =Anything that has mass and
volume.
ELEMENT = any one kind of atom (helium,
oxygen, carbon, etc…)
= the periodic table is all of the
elements that we know of in
our universe
• Solving the puzzle of the periodic table.
[VIDEO]
Anatomy of the Atom:
An atom is made up of a:
Nucleus = dense center where
virtually all of the mass of the
atom is found. It is made up of:
Protons (+charge)
and Neutrons (0 charge)
- The nucleus is surrounded
by orbiting Electrons (- charge)
- Electrons in orbit make up most of the
volume of the atom but have a mass
of virtually nothing.
Atom Animation - YouTube
• How small is an atom?
• How does an atomic accelerator Work?
Elements:
Atomic # (Number of
Protons and # of
Electrons)
7
N
Nitrogen
14.0067
Atomic Symbol
Element Name
Atomic Mass
• Atomic # = # of Protons (and the # of
electrons before an atom reacts)
• Atomic Mass = # of Protons + # of
Neutrons (components of Nucleus)
• Mass = # Protons + # of Neutrons
______ = _____
+ ______
interactive periodic table
Assignment: Please complete handout on
“Element information”.
Build an Atom - Atomic
Structure, Atoms, Atomic Nuclei
- PhET
Creation of Compounds: Why do Atoms Bond
Together?
• All elements have electrons orbiting around the
nucleus’s. There can be 1, 2 or many orbits and
each orbit can hold a different amount of
electrons.
• Chemical Reactions - Periodic Table of Videos YouTube
1st Orbit = 2 electrons
2nd orbit = 8 electrons
3rd orbit = 8 electrons
4th orbit = 18 electrons
Each atom is trying to have a full
orbit of electrons!
• How Atoms Bond -
Chemical reactions result when two or more atoms
come together in such a way as to fill their outer electron
shells (valence shells).
Reaction s can be one of two main types:
Ionic bond
• In an ionic bond one atom has such a strong attraction
for the electrons (electro-negativity) that it pulls an
electron away from another atom. This results in the
two atoms now having charge.
Covalent Bond
• A covalent bond generally forms when two
atoms of the same element are bonded together
Since the atoms have the same attraction for
electrons (electronegativity) neither atom can
completely remove an electron from the other
and as a result they share the electrons equally.
• Ionic and covalent bonding animation - YouTube
Objective 6: First Nations P of V
• Please read the article and answer the
following questions:
Objective 7: History of Atomic
Model (Aristotle(360BC),
Dalton(1803), Thomson(1897),
Rutherford(1911),Bohr(1922)
1 Aristotle (Greek era)
– Atom = uncuttable
-(smallest form of a
particle)
-4 elements made up
everything else
Dalton (1803)
• Based theories on Experimentation
• Came up with the atomic theory:
– 1. All elements are made up of invisible
atoms.
– 2. Atoms of the same element are identical.
– 3. Atoms of different elements combine to
form compounds.
– 4. Chemical reactions are the rearrangement
of atoms but atoms cannot be split. (This is
the only part of his theories that has later
been disproved!)
Thomson (1897)
• Provided 1st evidence that atoms are
made of even smaller particles with
charges.
• Made the Plum Pudding analogy
Rutherford’s Atomic Model
• Rutherford developed a new model for
the atom.
• An atom has a tiny, dense positive core
called the nucleus (which deflected the
alpha particles and contains protons.)
• The nucleus is surrounded mostly by
empty space, containing rapidly moving
negative electrons (through which alpha
particles pass unhindered.)
Atomic Models: Bohr
• Niels Bohr proposed a
“planetary” model of the
atom.
• Electrons are found in
specific energy levels
called orbits
– Like planets around the
sun
• Each electron in an orbit has a definite
amount of energy.
• The further the electron is from the nucleus,
the more energy it has.
• Electrons do not exist between the orbits but
can move from one orbit to another.
• The order of filling of electrons in the first
three orbits is 2, 8, 8.
• Electrons are more stable when they are at
lower energy, closer to the nucleus.
Bohr Diagrams
• Bohr’s model was
readily accepted by
scientists and they
began drawing
models of the atom
using his theory.
Bohr-Rutherford Diagrams
• This diagram is a combination of
Rutherford's nuclear model and Bohr’s
planetary model.
• It summarizes all of the sub atomic
particles in the atom
Chlorine
17 p+
18 n0
Structure of the Atom 1: The Earliest Models - YouTube
Scroedinger – Present Atomic Model
Based on wave mechanics and the
probability of where electrons would be
found about the nucleus.
HowStuffWorks "Assignment Discovery: Origin of the Atom Theory"
Objective 8: Elements,
Compounds, and Mixtures
A Chemical reaction:
-Involves a transfer of electrons (Ionic)
OR a sharing of electrons (Molecular)
-Happens as elements try to fill an
outer orbital (Valence electrons)
We can describe a molecule or compound
based on how many atoms of each element
it possesses.
2 forms of Gasoline
• When 2 or more elements react (Compound)
a FORMULA is used to describe the
reaction.
What is this?
Nitrogen: 20-90%
Hydrogen: 0-50% (flammable)
Carbon dioxide: 10-30%
Oxygen: 0-10%
Methane: 0-10% (flammable)
Examples of Compounds
Examples of Formulas for
compounds
Examples of names of
common compounds
H2O
Water
C6H12O6
Glucose
C2H6O
Alcohol
NaCl
Salt
C2H6O
Ethanol
C2H4O2
Vinegar
NH3
Ammonia
C2H4O2
Acetic Acid
C4H10
Butane
H2SO4
Sulfuric Acid
CH4
Methane
C12H22O11
Sucrose
C3H8
Propane
NaHCO3
Baking Soda
N2O
Nitrogen
C6H8O7
Citric Acid
C8H18
Octane
C10H16O
Camphor
Objective 9: Structure of
Common Elements
Planetary models of the first 18 elements
assignment
Crossword on elements
Article on castle of elements
Objective 10: Chemical Symbols
and Formulas in Compounds
• Chemicals React! – All elements want to
become like the Noble gases (with a full
outer orbital of electrons) and will react
with other elements until they do.
• As a result electrons will be gained or lost.
• All chemical reactions must follow the
basic law of “Conservation of Matter”.
Skill #1
• Accounting for Atoms in a Molecule:
• A formula is the correct combination of elements into an
particular molecule. It is very dependant on the correct
listing of atoms and amounts of each.
What elements are in these molecules and how
many are there?
SULFURIC ACID
Handout
-
H2SO4 =
SUGAR
C6H12O6 =
CAFFEINE
C8H10N4O2 =
Rules for Writing a Chemical Formula:
1.
Lower case #’s (subscript) refer only to the element
immediately preceding the #.
Eg. Na2 =
2.
A lower case # (subscript) after a set of brackets refers
to all the atoms within the brackets preceding the #.
Mg(OH) 2 =
3.
A large # in front of the atoms (“Coefficient”) refers to
all the atoms following the # in that molecule.
2NaCl =
4.
When trying to determine the #’s of atoms, multiply the
Coefficient in front by the lower case #’s behind of
elements.
2Ca(OH) 2 =
Handout Answers
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
2 H, 2 Cl
2 H, 1 S, 4 O
2 Na, 6 Cl
6 Na, 12 O, 12 H
2 H, 2 S, 6 O
4 H, 2 C, 4 O
36 C, 72 H, 36 O
1 Na, 1 Cl
2 B, 2 S
4 Na, 8 Cl
1 As, 3 C, 3N
Same as 23
2 Ba, 1 Si
13. 3 H, 1 P, 3 O
14. 1 H, 1 P, 3 O
15. 1 H, 1 C, 1 N
16. 2 H, 2 S, 7 O
17. 3 Ag, 1 P, 4 O
18. 1 Co, 3 Cl
19. 1 Fe, 3 Mn, 12 O
20. 2 N, 4 H, 2 O
21. 2 Al, 3 S
22. 1 Zn, 2 I, 8 C
23. 1 Ni, 2 As, 6 O
24. 2 I, 7 O
25. 1 Au, 1 N, 1 S, 3 O
Skill #2
• Reaction Types: Describe a reaction as being
either:
– Synthesis (smaller elements or molecules react to
form larger ones)
- Decomposition (larger molecules get broken down
into smaller ones)
– Single Replacement (One element in a molecule
gets traded for some new element stepping in)
– -Double Replacement (elements from 2 different
molecules switch partners)
– Combustion (A compound rectas with Oxygen and
the products have some new molecule)
Eg. Burning of Methane:
1 CH4 + O2 ----} CO2 + 2 H2O
Skill #3 Balancing Equations
• The Law of Conservation of Mass:
– 1 Matter cannot be created or destroyed.
– 2 The total mass of all reactants before a
chemical reaction must be the same as
the total of all products after the chemical
change has taken place.
How to Balance a Reaction:
• 1. Adjust the numbers of each kind of atom by writing
COEFFICIENTS in front of the formulas of the
compounds and elements.
• 2. DO NOT use subscripts as this changes what the
molecule is! Eg. (H2O ----} not H2O2 but 2H2O
Examples:
1. H2O ----} H2 + O2
2. Na + Cl2 ------} NaCl
3. Fe + H2O --------} Fe2O3 + H2
Objective 11: History and
Organization of the Periodic Table
• The Periodic Table: Crash Course Chemistry #4 - YouTube
• The genius of Mendeleev's periodic table - Lou Serico – YouTube
• Solving the puzzle of the periodic table - Eric Rosado - YouTube
• Please complete the following textbook reading: Pg177188,190 Answer questions on pg 188 – (1,4,5,6,7) Pg
191 – (2,3,4)
Mendeleev’s table from 1869
Objective 12:
• Please complete the handout (Element
Squares and Planetary Info.) as a review
of Atomic Information found on the
Periodic Table: