Chem 1020 The Chemical World Chapter 1
Review Question with Verified Correct Answers
Define chemistry
The science that tries to understand how matter behaves by studying how atoms and
molecules behave.
What is the difference between a law and a theory?
A scientific law only says "what" happens. It summarizes past observations and predicts
future ones. A scientific theory explains "why" things happen. It provides a broader and
deeper explanation for observations and laws.
What is the difference between a hypothesis and theory?
Before a theory is well established, it is called a hypothesis.
What is wrong with the statement, "It is just a theory"?
Theories are well established and have been vetted/tested multiple times. While a theory can
never be "fully" proven, theories are accepted as fact within the scientific community unless
proven otherwise.
What is the law of conservation of mass, and who discovered it?
Lavoisier developed the law of conservation of mass, which states, "In a chemical reaction
matter is neither created nor destroyed."
What is atomic theory, and who formulated it?
John Dalton (1766-1844) explained the law of conservation of mas, as well as other laws and
observations, by proposing that all matter was composed of small, indestructible particles
called atoms.
, Classify each statement as an observation, a law, or a theory.
(a) When a metal is burned in a closed container, the sum of the masses of the container
and it's contents does not change
(b) Matter is made of atoms
(c) Matter is conserved in chemical reactions
(d)When wood is burned in a closed container, its mass does not change.
(a) Observation
(b) Theory
(c) Law
(d) Observation
Classify each statement as an observation, a law, or a theory.
(a) The star closest to earth is moving away from Earth at high speed.
(b) A body in motion stays in motion unless acted upon by a force.
(c) The universe began as a cosmic explosion called the Big Bang
(d) A stone dropped from an altitude of 450m falls to the ground in 9.6s.
(a) Observation
(b) Law
(c) Theory
(d) Observation
Which statement most resembles a scientific theory?
(a) When the pressure on a sample of oxygen gas is increased 10%, the volume of the
gas decreases by 10%.
(b) The volume of a gas is inversely proportional to its pressure.
Review Question with Verified Correct Answers
Define chemistry
The science that tries to understand how matter behaves by studying how atoms and
molecules behave.
What is the difference between a law and a theory?
A scientific law only says "what" happens. It summarizes past observations and predicts
future ones. A scientific theory explains "why" things happen. It provides a broader and
deeper explanation for observations and laws.
What is the difference between a hypothesis and theory?
Before a theory is well established, it is called a hypothesis.
What is wrong with the statement, "It is just a theory"?
Theories are well established and have been vetted/tested multiple times. While a theory can
never be "fully" proven, theories are accepted as fact within the scientific community unless
proven otherwise.
What is the law of conservation of mass, and who discovered it?
Lavoisier developed the law of conservation of mass, which states, "In a chemical reaction
matter is neither created nor destroyed."
What is atomic theory, and who formulated it?
John Dalton (1766-1844) explained the law of conservation of mas, as well as other laws and
observations, by proposing that all matter was composed of small, indestructible particles
called atoms.
, Classify each statement as an observation, a law, or a theory.
(a) When a metal is burned in a closed container, the sum of the masses of the container
and it's contents does not change
(b) Matter is made of atoms
(c) Matter is conserved in chemical reactions
(d)When wood is burned in a closed container, its mass does not change.
(a) Observation
(b) Theory
(c) Law
(d) Observation
Classify each statement as an observation, a law, or a theory.
(a) The star closest to earth is moving away from Earth at high speed.
(b) A body in motion stays in motion unless acted upon by a force.
(c) The universe began as a cosmic explosion called the Big Bang
(d) A stone dropped from an altitude of 450m falls to the ground in 9.6s.
(a) Observation
(b) Law
(c) Theory
(d) Observation
Which statement most resembles a scientific theory?
(a) When the pressure on a sample of oxygen gas is increased 10%, the volume of the
gas decreases by 10%.
(b) The volume of a gas is inversely proportional to its pressure.
