Transcript Online Review Game

Unit #1: INTRODUCTION
INTERNET REVIEW GAME
Chapter 1: Matter and Energy
Chemistry Is a Physical Science
Matter and Its Properties
Elements

Q1: Define a physical property. List two examples of
physical properties.
Answer: A property that can be observed or
measured without changing the identity of the
substance. Examples include color, odor, length,
size and melting point.
Q2: How can you tell the difference between an
element and a compound?
Answer: Compounds can be separated into
elements by chemical means. Elements cannot
be separated into simpler substances by
chemical means.
Q3: Identify each of the following as either a physical
change or a chemical change. Explain your answers.
a. A piece of wood sawed in half
b. Milk turns sour
c. Melted butter solidifies in the refrigerator
Answer:
a. physical, because the wood remains wood
b. chemical, because the milk changes
composition, as signified by the change in flavor
c. physical, because the butter remains butter
Q4: Write a brief paragraph that shows that you
understand the following terms and relationships
between them: atom, molecule, compound and
element
Answer: A molecule is the smallest unit of a
substance that keeps all of the physical and
chemical properties of that substance. An
element is composed of molecules that can be
single atoms or more than one kind of the same
atom. A compound is composed of two or more
elements, so a molecule of a compound is made
up of two or more different kinds of atoms.
Q5: Pick an object that you can see right now. List
three of the object’s physical properties that you can
observe. Can you also observe a chemical property
of the object? Explain you answer.
Answer: Obviously your answers will vary.
Physical properties include shape, texture, state
of matter, and taste. Chemical properties could
not be observed unless a chemical change was
attempted.
Q6: Magnesium reacts with hydrochloric acid to
produce magnesium chloride and hydrogen gas. The
reactants in this reaction are
a. magnesium and magnesium chloride
b. hydrochloric acid and hydrogen gas
c. magnesium and hydrochloric acid
d. magnesium chloride and hydrogen gas
Answer: c. magnesium and hydrochloric acid
Q7: Matter that has a definite shape and a definite
volume is
a. a liquid
b. an element
c. a solid
d. a gas
Answer: c. a solid
Q8: We know that air is a mixture and not a
compound because
a. it can be heated to a higher temperature
b. it can be compressed to a smaller volume
c. it is colorless
d. its composition can vary
Answer: d. its composition can vary
Q9: Matter can be defined as anything that
a. has weight
b. has mass and volume
c. is uniform throughout
d. exhibits both chemical and physical
properties
Answer: b. has mass and volume
Q10: Which of the following is best classified as a
homogenous mixture?
a. pizza
b. blood
c. hot tea
d. copper wire
Answer: c. hot tea
Q11: A compound differs from a mixture in that a
compound
a. contains only one element
b. varies in chemical composition
depending on the sample size
c. has a definite composition by mass of
elements that the compound contains
d. can be classified as either heterogeneous or
homogeneous
Answer: c. has a definite composition by mass of
elements that the compound contains
Q12: Which of the following is not a physical state of
matter?
a. solid
b. gas
c. element
d. liquid
Answer: c. element
Q13: Three of the following must contain two or more
kinds of atoms. Which one does not contain two or
more kinds of atoms?
a. element
b. compound
c. homogeneous mixture
d. heterogeneous mixture
Answer: a. element
Q14: Which of the following symbols does not match
the element given?
a. Al, Aluminum
b. Co, copper
c. K, potassium
d. P, phosphorus
Answer: b. copper is actually Cu
Q15: In trying to identify a sample of a pure
substance, we observe the following properties. Tel
whether each one is a chemical property or a physical
property.
a. Its mass is 124.3 g
b. It is a shiny solid at room temperature
c. It is easily etched by nitric acid
d. It melts when heated to 670oC
e. It is 31.7 centimeters long
f. It is a good heat conductor
g. It burns in air
h. It is a good conductor of electrical energy
Answer: Observations c and g are chemical properties;
the others are physical properties
Q16: Describe the difference between a chemical
change and a physical change. Give one example of
each kind of change.
Answer: In a chemical change, one or more of
substances are converted into different
substances. A physical change does not involve
a change in the identity of the substances
present. Examples will vary.
Q17: Describe general properties of metals,
nonmetals and metalloids.
Answer:
 Metals: shiny, good conductors of heat; good
conductors of electricity; malleable or ductile; most are
solids at room temperature.
 Nonmetals: poor conductors of heat and electricity;
many are gases at room temperature; those that are
solids are brittle rather than malleable or ductile.
 Metalloids: properties are between those of metals and
nonmetals.; less malleable than metals but not as brittle
as solid nonmetals; most are semiconductors of
electricity.