THE FOLLOWING SLIDES ARE REVIEW OF
HOMEWORK 8-10 (PACKET)
1) The four diagrams below model the results of mixing atoms of
different substances. Each atom is represented by a different
symbol. Which diagram correctly models a chemical change?
a)
b)
c)
d)
2) The table below shows the chemical symbols for common
elements.
Based on the information in the table, which of the 4
substances below is a compound?
a) CO
b) He
c) Si
d) Fe
3) The diagram below shows a rock sample and an
identification key.
This rock sample is an example of
a) an element
b) compound
c) heterogeneous mixture
d) homogeneous mixture
4) Some common substances and their chemical formulas
are listed in the chart below
Which of these substances are elements?
a) hydrochloric acid
b) carbon dioxide and water
c) oxygen and helium
d) water and oxygen
5) The illustration below shows a solid metal ball and a ring
before and after heat is applied to the metal ball. Before heat
is applied, the metal ball passes easily through the ring. After
heat is applied, the metal ball does not pass through the
ring.
What evidence shows that a physical change took place in the
metal ball?
Ans: The ball would not pass through the ring anymore
after it was heated because its size changed.
***6) Magnets A and B are of equal magnetic strength. In
which position will the magnets A and B have the
greatest attractive force toward each other?
a)
c)
b)
d)
7) A chemical property of a mineral is evident if the mineral
a) breaks easily when struck with a hammer
b) bubbles when acid is placed on it
c) is easily scratched by a fingernail
d) reflects light from its surface
8) Equal–sized pieces of aluminum were placed in test tubes
containing equal volumes of acid, at different temperatures. The
temperature of the acid is test tube A is 5oC. The temperature of
the acid in test tube B is 20oC. What observation would indicate
that a chemical reaction is taking place in the test tubes?
Ans: Bubbles start to form
10) Hydrochloric acid is added to a beaker containing a piece of zinc.
As a result, zinc chloride is formed and hydrogen gas is released.
This is an example of
a) physical change
b) chemical reaction
c) homogeneous mixture
d) heterogeneous mixture
11) Which one of the following characteristics represents a chemical
property?
a) Reactivity
b) Malleability
d) Color
c) Solubility
e) Melting Point
12) Sand and iron particles that a similar in size and color are mixed
together in a beaker. What would be the best method in
separating the particles?
a) Use tweezers to separate them b) Use a magnet to separate them
c) Add water to separate the mixture d) Pour the mixture into a
filter
13) Which action forms a different chemical substance?
a) crushing a rock
b) burning a piece of wood
c) mixing salt and pepper
d) melting an ice cube
14) A baseball strikes the roof of a car and dents it. The paint on the
roof begins to crack and chip, exposing the metal. The exposed
metal on the roof rusts, eventually causing a small hole in the
roof. Which event is a chemical change?
a) The baseball strikes the roof
dents
b) The roof of the car
c) The paint cracks and chips
d) The exposed metal rusts
15) List one observation that shows a chemical change is occurring in
the diagram.
Ans: Bubbles start to form
16) Identify the soluble material, the insoluble material, and the
solvent.
Salt
Soluble
material_____________________________________________
Sand
Insoluble material: _______________________________________
Water
Solvent: ________________________________________________
.
17) Explain why the contents of the flask in Figure B are classified as
a mixture.
Ans: The substances are combined with
NO chemical change
.
18) Explain why only solid salt particles remain in the flask in figure
C.
Ans: The water evaporated (liquid to gas)
***25) The flask and its contents had a mass of 120 grams
before the experiment and a mass of 120 grams after the
experiment. Which conclusion can best be made from these
measurements?
a) a phase change took place
b) Energy was destroyed
c) Matter was conserved
d) New elements were formed
26) The chemical change that occurred in the flask is most
similar to
a) burning a piece of coal
b) freezing water in a container
c) breaking a piece of wood into many pieces
d) bending a wire to form a hook
Create flashcards for the following words. Get into pairs and
quiz each other. Prepare for quiz toward end of the period.
Definitions:
1) Atom: lego blocks of all matter
2) Matter: anything that takes up space
3) Element: type of atom
4) Molecule: 2 or more atoms connected at electrons
5) Compound Molecule: molecule with different elements
6) Chemical Reaction (Change): when new molecules are formed
7) Fusion: nuclei of more than one atom combine to form a new
element
Create flashcards for the following words. Get into pairs and
quiz each other. Prepare for quiz toward end of the period.
Definitions:
8) Reactants: molecules/atoms you begin with (left of arrow)
9) Products: molecules/atoms you end with (right of arrow)
10) Physical Change: change in physical characteristic but NO
new molecules formed
11) Coefficient: Big # before molecule. Tells am’t of molecules
12) Subscript: lower # in a molecular formula. Tells am’t of
atoms
13) Mixture: physical combination of things but NO
chemical change
Create flashcards for the following words. Get into pairs and quiz
each other. Prepare for quiz toward end of the period.
Definitions:
14) Heterogeneous Mixture: mixture where you can see the
different substances
15) Homogeneous Mixture: mixture where everything looks
the same
16) Solution: homogeneous mixture where something dissolves
17) Soluble: Can dissolve
18) Insoluble: Can not dissolve
19) Solute: The thing dissolving
20) Solvent: the thing that a substance dissolves in
Additional Vocabulary:
21) Temperature
22)State of matter
22) Phase Change
23) Condensation
24) Evaporation
25) Sublimation
25) Boiling point
26)Melting point