CHEM 103 EXAM 1 QUESTIONS WITH
CORRECT ANSWERS 2026
What is chemistry? - CORRECT ANSWER -Chemistry is the study of the physical and
compositional changes of matter.
Chemistry is called the Central Science.
Many health related areas of study are based on Chemistry.
Matter - CORRECT ANSWER -Matter is anything that has mass, occupies space and is made-up of
atoms or parts of atoms.
Mass - CORRECT ANSWER --Mass is a measure of the amount of matter in an object.
-Mass is independent of the location of an object.
-An object on the earth has the same mass as the same object on the moon, but not same
weight.
Weight - CORRECT ANSWER --Weight is a measure of gravitational force acting on object.
-Weight depends on the location of an object.
-Force = Mass * Acceleration, F = ma, Wt = m(gravity).
-An object weighing 1.0 lb on earth, weighs about 0.17 lb on the moon. Mass of object is
constant. Moon has 1/6 gravity of earth, which reduces apparent weight of object.
Physical Properties of Matter - CORRECT ANSWER --Physical properties can be observed or
measured without changing the composition of the matter being observed.
, Examples of physical properties are: color, shape and mass, and all changes of state like gas to a
liquid.
Chemical Properties of Matter - CORRECT ANSWER --Chemical properties can be observed or
measured only when the composition of matter is changed.
Examples of chemical properties are flammability and the ability to react (e.g. when vinegar and
baking soda are mixed). Atoms must change partners.
Physical changes of Matter - CORRECT ANSWER --Physical changes are reversible.
-Physical changes take place without a change in composition. Atoms are not changing partners.
-Nothing new is being created.
Examples of physical changes are freezing, melting, or evaporation of a substance (e.g. water).
H2O(s) → H2O(l), ice → water.
Separation of compounds is a physical change.
ex/ separating iron filing from sand is a chemical reaction
Chemical Changes of matter - CORRECT ANSWER --Chemical changes are not always reversible.
-Chemical changes are always accompanied by a change in composition. Atoms are changing
partners.
-New types of matter are being created, O2 + 2H2 → 2H2O
Examples of chemical changes are the burning of paper and the fizzing of a mixture of vinegar
and baking soda.
Democritus (Greek, 460-370 BC) - CORRECT ANSWER -First person whose writings suggested,
-based only on logic, that atoms where the
basis of matter.
-Atoms comes from the word 'atomos'
CORRECT ANSWERS 2026
What is chemistry? - CORRECT ANSWER -Chemistry is the study of the physical and
compositional changes of matter.
Chemistry is called the Central Science.
Many health related areas of study are based on Chemistry.
Matter - CORRECT ANSWER -Matter is anything that has mass, occupies space and is made-up of
atoms or parts of atoms.
Mass - CORRECT ANSWER --Mass is a measure of the amount of matter in an object.
-Mass is independent of the location of an object.
-An object on the earth has the same mass as the same object on the moon, but not same
weight.
Weight - CORRECT ANSWER --Weight is a measure of gravitational force acting on object.
-Weight depends on the location of an object.
-Force = Mass * Acceleration, F = ma, Wt = m(gravity).
-An object weighing 1.0 lb on earth, weighs about 0.17 lb on the moon. Mass of object is
constant. Moon has 1/6 gravity of earth, which reduces apparent weight of object.
Physical Properties of Matter - CORRECT ANSWER --Physical properties can be observed or
measured without changing the composition of the matter being observed.
, Examples of physical properties are: color, shape and mass, and all changes of state like gas to a
liquid.
Chemical Properties of Matter - CORRECT ANSWER --Chemical properties can be observed or
measured only when the composition of matter is changed.
Examples of chemical properties are flammability and the ability to react (e.g. when vinegar and
baking soda are mixed). Atoms must change partners.
Physical changes of Matter - CORRECT ANSWER --Physical changes are reversible.
-Physical changes take place without a change in composition. Atoms are not changing partners.
-Nothing new is being created.
Examples of physical changes are freezing, melting, or evaporation of a substance (e.g. water).
H2O(s) → H2O(l), ice → water.
Separation of compounds is a physical change.
ex/ separating iron filing from sand is a chemical reaction
Chemical Changes of matter - CORRECT ANSWER --Chemical changes are not always reversible.
-Chemical changes are always accompanied by a change in composition. Atoms are changing
partners.
-New types of matter are being created, O2 + 2H2 → 2H2O
Examples of chemical changes are the burning of paper and the fizzing of a mixture of vinegar
and baking soda.
Democritus (Greek, 460-370 BC) - CORRECT ANSWER -First person whose writings suggested,
-based only on logic, that atoms where the
basis of matter.
-Atoms comes from the word 'atomos'
