Introductory Chemistry, 5e (Tro)
Chapter 1 The Chemical World
True/False Questions
1) Chemicals make up everything around you, including your own body.
2) Chemists study the properties of substances and the particles that compose those substances.
3) When a sealed can of soda pop is opened, the carbon dioxide gas fizzes out because the
pressure is released.
4) Different molecules can have different shapes.
5) The properties of water do not depend on how the atoms are bonded together in the molecule.
6) Both carbon dioxide molecules and water molecules consist of three atoms bonded together in
a straight line.
7) Molecules are responsible for scattering light which causes the colors of the sunset.
8) All things are made of atoms or molecules.
9) Atoms and molecules determine how matter behaves.
10) Chemistry is the science that seeks to understand what matter does by studying living
organisms.
11) The scientific method emphasizes reason as the way to understand the world.
12) A hypothesis can never be proven as wrong.
13) A theory is always true and can never be proven as wrong.
14) Theories can be tested and validated through experimentation.
15) If experimental results contradict a hypothesis, the hypothesis must be either revised or
discarded.
16) The Greek philosophers used observation and experimentation to understand the world.
17) A scientific law is a brief statement that summarizes past observations and predicts future
ones.
18) The law of conservation of mass states, “In a chemical reaction matter can be created and
destroyed.”
19) Antoine Lavoisier observed that burning objects in a closed container resulted in a loss of
mass.
20) A scientific theory describes the underlying reasons for observations and laws.
21) The scientific method ensures that poor theories are eliminated over time and good theories
remain.
22) A theory is the equivalent of an opinion.
23) Antoine Lavoisier proposed the atomic theory.
24) John Dalton proposed the atomic theory.
25) The first step in acquiring scientific knowledge is often the observation or measurement of
some aspect of nature.
26) If a hypothesis is falsifiable, it means that the hypothesis was once considered true but is now
considered false.
27) Observations from experiments are used to test theories.
28) A theory can only exist after many experiments have validated a hypothesis.
29) Scientific theories are also called models.
30) The atomic theory explains why the law of conservation of mass is true.
31) An established theory is the pinnacle of scientific understanding.
32) Quantification is an important tool in understanding chemistry.
33) Lavoisier developed the law of conservation of mass.
34) Combustion means burning.
35) The phlogiston theory of combustion is still considered correct today.
36) Quantification involves measurement as part of an observation.
Multiple Choice Questions
1) Which of the following statements about soda pop is FALSE?
A) Soda pop is a chemical mixture of mostly sugar, water and carbon dioxide.
B) The molecules important to fizzing are carbon dioxide and water.
C) The carbon dioxide is forced to mix with the water by the presence of sugars.
D) When a can is opened, the pressure release allows carbon dioxide to form bubbles.
E) All of the above statements are true.
2) Which of the following items does NOT contain chemicals?
A) drain cleaner
B) organically grown vegetables
C) air
D) insecticides
E) All of the above contain chemicals.
3) A good definition of chemistry is:
A) the science that seeks to understand what matter does by studying what atoms and molecules
do.
B) the science that seeks to understand what living organisms do by studying the molecules that
make up the organism.
C) the science that seeks to understand what the universe does by studying interactions of
molecules with atoms.
D) the science that seeks to understand the interactions of molecules for the sake of advancing
human control over nature.
E) none of the above
4) Which statement about the scientific method is TRUE?
A) The scientific method emphasizes reason as the way to understand the world.
B) The scientific method emphasizes observation and reason as the way to understand the world.
C) The scientific method emphasizes observation and experimentation as the way to understand
the world.
D) The scientific method emphasizes scientific laws as the way to understand the world.
E) All of the above statements are false.
5) Which of the statements below is NOT part of the scientific method?
A) observation and measurement
B) formation of a hypothesis
C) testing of a hypothesis by experimentation
D) refinement of a hypothesis as needed
E) All of the above steps are part of the scientific method.
6) Which statement about a hypothesis is TRUE?
A) It is a tentative interpretation or explanation.
B) It has the potential to be proven wrong.
C) It can be tested by experiments.
D) It is part of the scientific method.
E) All of the above statements are true.
7) The definition of a scientific law is:
A) the same as a hypothesis.
B) a way of learning that emphasizes observation and experimentation.
C) the underlying reason for a scientific theory.
D) a number of similar observations generalized into a brief statement summarizing past
observations and predicting new ones.
E) none of the above
8) What term best describes a brief statement that summarizes many past observations and
predicts new ones?
A) experiment
B) hypothesis
C) scientific law
D) theory
E) none of the above
9) Who discovered the law of conservation of mass?
A) John Dalton
B) Antoine Lavoisier
C) Nivaldo Tro
D) John Dalton and Antoine Lavoisier
E) none of the above
10) Which of the following is an example of a scientific law?
A) All matter is composed of small, indestructible particles called atoms.
B) In a chemical reaction, matter is neither created nor destroyed.
C) When a can of soda pop is opened, a fizzing sound is heard.
D) Flammable objects contain phlogiston.
E) none of the above
11) What is the definition of a scientific theory?
A) a brief statement that summarizes past observations and predicts future ones
B) a model that explains the underlying reasons for observations and laws
C) the equivalent of a scientific opinion which others may disagree with
D) a method of learning that emphasizes reason as the way to understand the world
E) none of the above
12) Who discovered the atomic theory?
A) John Dalton
B) Antoine Lavoisier
C) Nivaldo Tro
D) John Dalton and Antoine Lavoisier
E) none of the above
13) Which of the following is an example of an observation?
A) All matter is composed of small, indestructible particles called atoms.
B) Reactions occur due to the transfer of electrons.
C) When a can of soda pop is opened, a fizzing sound is heard.
D) Flammable objects contain phlogiston.
E) none of the above
14) A sample of wood with a mass of 3.0 grams was burned in an open dish. The ashes weighed
1.2 grams. What happened to the rest of the wood?
A) The remaining mass was destroyed.
B) The remaining 1.8 grams was converted into gaseous compounds.
C) Nothing, the burned wood simply has a mass of 1.2 grams.
D) The remaining 1.8 grams was converted into heat.
E) none of the above
15) Which statement accurately describes the purpose of experiments?
A) Experiments are designed to produce the results predicted by a theory.
B) Experiments can be replaced by a simple, logical reasoning of known facts.
C) Experiments are designed to produce unexplainable results for further investigation.
D) Experiments look for other observable predictions of a theory.
E) none of the above
16) Which of the following would be considered a theory?
A) Glass is fragile.
B) Hot air rises.
C) Gasoline has a very strong odor.
D) Helium balloons float because helium is less dense than air.
17) Which of the following is considered a hypothesis (as opposed to an observation)?
A) Spiders have eight legs.
B) Birds can fly because they have hollow bones.
C) Fresh lava from a volcano is hot.
D) The Washington Monument is 555 feet tall.
E) none of the above
18) The key to success in chemistry is:
A) curiosity.
B) mathematical skills.
C) commitment.
D) practice.
E) all of the above
19) Which statement would NOT be an example of “quantification”?
A) The newest model of that car gets five more miles per gallon than last year’s model.
B) The price of milk went up ten cents per gallon.
C) The average high temperature this July was two degrees higher than last year’s average high
temperature.
D) The water in the swimming pool feels colder than it was yesterday.
E) none of the above
Essay Questions
1) What is chemistry?
2) What are the important characteristics of the scientific method?
3) What is the difference between a scientific law and a scientific theory?
4) Charcoal was burned in a barbecue grill. The ashes that remained weighed considerably less
than the charcoal that was burned. Does this mean that the law of conservation of mass is wrong?
Explain.