Chapter 3

Question 1

Solid:

Answer 1

definite shape, definite volume
* has same shape and volume no matter what
* atoms/molecules are in fixed positions, close to each other
* atoms/molecules do not flow, so they cannot be
compressed, but they can vibrate

Question 2

Liquid:

Answer 2

indefinite shape, definite volume
* has the same volume, but changes shape to fit the
container it is in
* atoms/molecules flow, but are touching so cannot be
compressed

Question 3

Gas:

Answer 3

indefinite shape, indefinite volume
* shape and volume change, always fills the container it is in
* atoms are farther apart and freely move, so can be
compressed

Question 4

Solid Crystalline Matter:

Answer 4

atoms or molecules are
arranged in geometric
patterns with long range
repeating unit
» Examples: table salt, NaCl

Question 5

Solid Amorphous Matter:

Answer 5

atoms or molecules do not have a
specific order or arrangements
» Examples: Glass, Rubber, Plastic

Question 6

Pure substance:

Answer 6

composed of only one type of
atom or molecule

Two types of pure substances:
1. Element
2. Compound

Question 7

Mixture

Answer 7

composed of two or more different
types of atoms or molecules combined in
variable proportions

Question 8

element

Answer 8

When it cannot be broken down into simpler
substances by any means
➢All known elements are listed in the periodic table
➢Examples: gold, silver, titanium, helium

Question 9

compound

Answer 9

when it can be broken down into constituent
elements by chemical means
➢contains definite or constant proportions
➢Example: water can be broken down into
hydrogen and oxygen atoms

Question 10

mixture

Answer 10

is a physical combination of two or more substances
in which each substance retains its own chemical identity
➢no set proportions
➢can be separated by physical means
➢Two types of mixtures:
1. Homogenous
2. Heterogeneous

Question 11

Physical properties

Answer 11

are the observed properties of a substance.
➢ Can be observed WITHOUT changing the identity of the substance.
➢ Examples: color, state (solid, liquid, gas), melting point, boiling point,
shape, odor, density
➢ Example: water is a clear, tasteless liquid (at room temp), it freezes at
0°C and boils at 100 °C

Question 12

Chemical Properties

Answer 12

are the known types of chemical changes
that will occur to a type of matter.
➢ Describes the way the substance undergoes or resists change TO
FORM A NEW SUBSTANCE
➢ flammability, decomposition, reactivity with air (rusting)
➢ Examples:
1. can send electricity through water and the water molecules break into
hydrogen and oxygen.
2. rusting of iron: iron combines with oxygen in air to form a new
material, rust

Question 13

2 types of Substance “binding forces”:

Answer 13

1. “Physical” binding forces - forces between particles that keep a
   substance together (most apparent in solids or liquids).
2. “Chemical” binding forces (chemical bonds) - forces within a
   single particle that keeps the particle itself together.
   ➢ The particle must be made up of more than 1 atom (molecule)
   for chemical binding forces to occur.

Question 14

Physical change:

Answer 14

Changes to particles that do not affect chemical
bonds; substance stays the same (i.e. mixing, breaking apart,
melting, freezing). “Inter-particle forces” affected only

Question 15

Chemical Change:

Answer 15

Changes to particles that affect chemical
bonds; new substance(s) formed from old substance(s). (i.e.
burning results in new substances formed).

Question 16

Decanting:

Answer 16

carefully pouring off the
liquid

Question 17

Distillation:

Answer 17

a process in which a mixture
is heated to boil off the more volatile (the
more easily vaporizable liquid)

Question 18

Filtration:

Answer 18

Used to separate insoluble solids from
liquids
➢The mixture is poured through filter
paper usually held in a funnel
➢Solid is left on the filter paper, while the
liquid passes through the paper into the
beaker

Question 19

Energy

Answer 19

Energy is the capacity to do work
* Work is defined as the result of a force acting on a distance
➢The behavior of matter is driven by energy
➢Understanding energy is critical to understanding chemistry

Question 20

law of conservation of energy

Answer 20

states that energy
is neither created nor destroyed
➢The total amount of energy is constant
➢Energy can be changed from one form to another
➢Energy can be transferred from one object to another
➢Energy cannot be created out of nothing, and it does
not vanish into nothing

Question 21

total energy

Answer 21

a sample of matter is the sum of its
kinetic energy and its potential energy

Question 22

Kinetic Energy

Answer 22

is the energy associated with motion

Question 23

Potential Energy

Answer 23

is the energy associated with position
or composition

Question 24

Electrical Energy

Answer 24

is the energy associated with the flow
of electrical charge

Question 25

Thermal Energy

Answer 25

the energy associated with the
random motions of atoms and molecules in matter
➢Temperature dependent
➢The hotter the object, the more thermal energy it contains

Question 26

Chemical Energy

Answer 26

is a form of potential energy
associated with the positions of the particles that
compose the chemical system

Question 27

High potential energy

Answer 27

= instability
* systems or objects with high potential energy have
a tendency to change in a way that lowers their
potential energy

Question 28

Exothermic Reactions

Answer 28

reactions in which energy is released
➢Heat flows from a system to its surroundings.
➢Reaction gives off heat, reaction vessel will feel warm/hot
➢Examples: Explosives, mixing water and acids

Question 29

Endothermic Reactions:

Answer 29

are reactions in which energy is absorbed.
➢Heat flows into a system from its surroundings.
➢Reaction absorbs head, reaction vessel will feel cold
➢Examples: Melting of ice, evaporation of acetone

Question 30

Heat

Answer 30

s the transfer or exchange of thermal energy caused
by a temperature difference

Question 31

Temperature

Answer 31

s a measure of the thermal energy of matter
➢Has units of temperature ( ̊F, ̊C, K )

Question 32

Heat Capacity

Answer 32

s the quantity of heat (usually in
joules) required to change the temperature of a given
amount of substance by 1 ̊C

Question 33

Specific Heat Capacity

Answer 33

also known as specific heat) is
the heat capacity of a substance expressed in grams.
Specific heat capacity has the units J / g ̊C

q is the amount of heat in joules
m is the mass of the substance in grams
C is the specific heat capacity in J / g ̊C
ΔT is the temperature change in ̊C
**the symbol Δ means the change in, ΔT = Final temperature – Initial temperature
* Must be done in °C