Unit 1 - Matter
Inertia: things like to keep doing what they are doing. If they are staying still they want to
stay still. If they are moving, they want to keep moving. In order to change what they are
doing (start/stop moving), something needs to happen (resistance or a push/pull).
Objective #1
a. define MASS
- The amount of stuff/matter in an object. The more mass an object has the lazier it is
because it has more inertia. Just because an object is larger in size doesn’t mean it
contains more mass.
b. define VOLUME:
-The amount of space an object takes up.
The law of conservation of mass:
Mass will NOT change if… something is enclosing the object as it changes. Bottom line:
-During physical and chemical change, overall mass does not increase or decrease, it just
moves around.
Objective #9: Density
Density is the amount of mass (stuff) per cubic centimeter or mL.
You can use the density to identify stuff, because each type of stuff has a unique density.
Objective #11
Use particle diagrams to represent solids, liquids and gases in a way that is consistent with
their densities.
Ratio: 3000 : 1000 : 1
Here are good
particle drawings of
different phases of
matter. They are
missing whooshies,
but otherwise fine.
Note relative
closeness of particles
in different phases.
Unit 2 Energy and Particle Motion
Objective #3: Describe the process of how the arrangement of particles changes
during phase changes
Particles attract each other. If they get too close, they repel each other, as if they are
connected with springs.
When melting, particles move faster until the latticework that holds them together is broken
so they can move all over.
Evaporation
liquid to gas
Happens at the surface of the liquid
Particles are colliding. During the collision, some get bumped so hard that they have
enough energy to escape the attraction to other particles in the liquid, and fly away as a gas
Heat makes the process faster
Boiling
Liquid to gas
Happens inside the liquid
Heat is added, and particles speed up. The extra energy lets them escape their mutual
attraction. They fly away from each other and become gases.
Because they are still inside the liquid, the gas particles form bubbles of vapor, which rise
to the top of the liquid, pop, and the vapor escapes
Condensation
Gas turning back into water
Happens when a warm gas contacts a warm surface
Particles slow down and get caught up by mutual attraction, form liquid
Expansion and contraction of substances during heating and cooling
Heating causes expansion
particles receive energy from heat
move faster, resist mutual attraction
move apart from each other
therefore the substance expands
EX: liquids - thermometer; solids - bridge; gases - hot air balloon
Cooling causes contraction
heat is removed, energy goes away from molecules
molecules get colder, can’t resist mutual attraction, move closer together
therefore the substance contracts
Unit 3: Energy and states of matter
Objective #1
Relate observations regarding the addition of energy by warming to increased particle
motion
 the more energy added, the more the particles move
 melting - particles break away from each other, begin to slide around
 heating - particles move faster and farther away from each other
 boiling/evaporating - particles more much faster and fly away from each other
Objective #2
Describe the characteristics of solids, liquids and gases in terms of particles and their
a. arrangement (particle drawings) (see particle drawings above) and
b. attraction (most attraction between particles of solid, and the least between particles of
gas)
Objective #3
Energy, like mass, is conserved during changes (see energy bar diagrams)
Objective #4
Energy makes things change - causes movement, heating, phase change, chemical
change.
Objective #7
Given a heating/cooling curve for a substance, identify what phase(s) is/are present in the
various portions of the curve, and what the melting and freezing temperatures are for the
substance.
Heating curve showing phases present, phase changes, and types of energy change
Cooling curve showing phases present, phase changes, and types of energy change
Objective #9
State the physical meaning of the heat of fusion (Hf) and heat of vaporization (Hv) for a
given substance. Use these factors to relate the mass of a substance to the energy
absorbed or released during a phase change (at the melting or boiling temperature).
During phase change, phase energy changes even though temperature doesn’t. The
question is how much energy is involved in melting, freezing, boiling or condensing a
substance?
A couple of important bits of info:
1. Obviously, the amount of energy involved depends on how much stuff you are
melting, freezing, etc….
2. Each substance requires or releases a unique amount of energy in melting,
boiling, etc.
Objective #10
State the physical meaning of the heat capacity (c) of a substance and use this factor to
relate the mass and temperature changes to the energy absorbed or released during a
change in temperature (with no phase change).
During temperature change, thermal energy changes even though phase doesn’t. The
question is how much energy is involved in heating or cooling a substance?
Heat capacity (hc) helps us find this out. It is the amount of energy required to heat a
substance, or released when a substance is cooled. Scientists have been able to
calculate these numbers, in amount of energy for one gram, for one degree Celsius
change. The trick is, each substance and each phase of a substance has a unique heat
capacity!
Unit 4 – Describing substances
Background information on particle drawings
elements: the same throughout
and
and
all represent elements
compounds: different types of elements bonded together
and
and
all represent compounds
Objective 1. Distinguish between a pure substance and a mixture by
 properties
 separation techniques
 composition (macro- and microscopically)
Mixture =
composition
more than one substance (different elements and/or compounds put together)
parts of a mixture are not chemically combined
properties are mixed - different boiling points, magnetism, etc.
can be seeen https://www.youtube.com/watch?v=qpDljy0U8zgparated by
physical means - magnet, filtration, distillation
particle drawings of mixtures
and
and
Pure substance =
composition one substance only: one type of element, or one type of compound.
if a compound, the elements that make up the compound are chemically combined
Properties are the same for all of a pure substance = same boiling point, etc.
They can be separated chemically. We observed hydrolysis in the lab (separating
water into its elements, hydrogen and oxygen) using the electricity in the Hoffman
apparatus)
Particle drawings of compounds
Objective 3. Cite evidence for the presence of “compounded” matter particles;
Describe the differences between elements and compounds
Compounds can be split into elements (like we split water into hydrogen and oxygen, using
the Hoffman apparatus).
Elements cannot be split into new substances. They can, however, be combined to form
new substances, like in the video where sulfur and iron reacted to form iron sulfate. And see
below…
Objective 4. State Avogadro’s Hypothesis (AH) and the evidence that led to this hypothesis.
Use AH along with combining volumes of gases to deduce the composition of some compounds
At equal temperature and pressure, equal volumes of different gases have equal numbers of
particles, even if the gas molecules are of different sizes.
See the Chem lab video to review this…
https://www.youtube.com/watch?v=qpDljy0U8zg
Objective 5 State features of Dalton’s model of the atom.
1. Some substances are composed of discrete amounts of two or more other
substances. (Example: red calyx decomposed to mercury and oxygen when heated;
water decomposed to hydrogen and oxygen through electrolysis.)
2. The total mass of the products in a chemical reaction is exactly equal to the mass of
the reactants. (Dalton’s Playhouse: Law of Conservation of Mass)
3. Elements combine in specific, defined ratios in chemical reactions.
(Dalton’s Playhouse, Worksheet #3… No matter how much of a compound is
analyzed, the ratio of elements is always the same.)
Unit 5, Counting Atoms
Objective 1. Use Avogadro’s Hypothesis and experimental data to determine the relative mass
of molecules.
1. Equal volumes of gases contain the same number of molecules at the same pressure and
temperature.
2. Note: Some pure elemental gases are clustered into pairs to form diatomic molecules, as
proved experimentally. They are … Br I N Cl H O F (bromine, iodine, nitrogen,
chlorine…)
There will be no mole calculations on this test! The main concepts are covered by particle
drawings; see below in notes for Unit 7.
Unit 6, Internal Structure of the Atom
Objective 2
Use the Thomson model of the atom to account for the fact that neutral atoms can become
either positively or negatively charged by the loss or gain of electrons.
a.
The body of the atom is positively charged. The electrons are negatively charged.
The complete atom is neutral. In order to get a charge, you have to acquire electrons
(negative charge) or else donate them (positive charge).
b.
Atoms are neutral until they react with another substance; then they become ions,
with a charge. E.g. copper has a neutral charge; when it reacts with another substance, like
silver nitrate, it becomes a copper ion Cu+ (and the silver ions Ag+ become silver atoms,
Ag, with a neutral charge).
c.
For a neutral atom to acquire a negative charge: it gains electrons.
THIS IS AN ANION
d. For a neutral atom to acquire a positive charge: it loses electrons.
THIS IS A CATION
e.
When metals and nonmetals react, the metals donate electrons to the nonmetals
a.
Electrons are...
b.
Negatively charged (magnets will deflect)
c.
Particles; they have mass; managed to measure mass:charge ratio
d.
Smaller than an atom
e.
All electrons are identical in size, mass, and charge.
f.
All matter has electrons, but matter it is usually neutral
g.
All matter also has positive charge; Thomson said that the positive charge
was everywhere else in the atom (dough). this positive charge balances the negative
charge of the electrons, and makes the total charge “0” or neutral
a.
Thomson’s experiments lead to his conclusion that atoms have a smaller particle
(the electron)
b.
c.
d.
e.
cathode ray tube experiment
the ray is made of electrons
the ray has a negative charge. He determined this by putting an object with a
negative charge next to the ray. The ray was repelled by the charge
(like charges repel). He then put an object with a positive charge next to the
ray. The ray was attracted to the positive charge (opposite charges attract).
the particles have mass
Unit 7 – Representing Chemical Change
Two main concepts here: conservation of mass and conservation of energy during chemical reactions
Left side of a chemical equation: reactants
Right side: products
There should be the same type and number of atoms on both sides of the equation. If not, the equation
is not balanced
A. Basic vocabulary
Subscript the number of a single type of atom or polyatomic ion, in a chemical formula
e.g. Ca(NO3)2. The “3” subscript means that there are three oxygen atoms for every one
nitrogen. The “2” subscript means that there are two nitrate ions for every one calcium ion.
e.g. CO2 + 2H2O  CH4 + O2
Coefficient the number of a particular molecule or element. The “2” means that there are 2 H2O
molecules used in this reaction.
B. Conservation of mass in chemical reactions
Note that the equation above is NOT balanced. This is so because there are only TWO oxygen atoms on
the reactant side, but FOUR oxygen atoms on the product side. To balance it, you would put a “2”
coefficient in front of the oxygen molecule:
CO2 + 2H2O  CH4 + 2O2
Particle drawings of balanced chemical equations
+

+
What if you start with more reactants than can be used in a reaction? You will get leftovers!
SO…
+
+

+
Extra CO2, not used in
the reaction, is still
hanging around,
mixed in with the
products
C. Conservation of Energy in chemical reactions
There will be no energy bar diagrams on the test. The concepts you need to know are:
1. During chemical reactions there is a transfer of energy between thermal and chemical
forms.
2. In endothermic reactions, when thermal energy is used to drive the reaction, this thermal
energy is stored in chemical bonds. Thermal energy is decreased, and chemical potential
energy increases, when chemical bonds are broken.
3. In exothermic reactions, when chemical energy is used to drive the reaction, the chemical
energy is changed into thermal energy. The chemical potential energy is released and
changed into thermal energy, when chemical bonds are formed.