Question 1

A molecule represented by O-O-O must be classified as
A)homoatomic and polyatomic.
B)homoatomic and monoatomic.
C)heteroatomic and polyatomic.
D)heteroatomic and monoatomic.

Accepted Answer

The molecule O-O-O, which consists of three oxygen atoms bonded together, is homoatomic because it is made up of atoms of the same element (oxygen) and polyatomic because it contains more than one atom.

Question 2

Which of the following represents a physical change in matter?
A)A substance solidifies at 443 K.
B)A substance produces a gas and a solid when heated.
C)A substance burns when heated.
D)A substance changes color when exposed to air.

Accepted Answer

Solidification is a physical change because it involves a change in the state of matter (from liquid to solid) without altering the chemical composition of the substance.

Question 3

Which of the following is a physical property of matter?
A)it does not burn
B)produces a gas when placed in an acid
C)freezes at − 10 ° F
D)the surface turns black in air

Accepted Answer

Freezing point is a physical property of matter, indicating the temperature at which a substance changes from a liquid to a solid state. Choices A, B, and D describe chemical properties or reactions, not physical properties.

Question 4

Which of the following is an example of a homogeneous mixture?
A)NaOH solution
B)mortar (mixture of water, sand and cement)
C)vinegar and oil salad dressing
D)more than one response is correct

Accepted Answer

A NaOH solution is a homogeneous mixture because it has a uniform composition throughout, where the solute (NaOH) is completely dissolved in the solvent (usually water), resulting in a single phase.

Question 5

Homoatomic pure substances are known as _____ .
A)protons
B)elements
C)compound
D)molecules

Accepted Answer

Homoatomic pure substances consist of only one type of atom, which defines them as elements.

Question 6

The mass of an object is
A)the force between the object and the earth.
B)a measure of the amount of matter in the object.
C)the amount of space the object occupies.
D)depends on the location of the object on the earth.

Accepted Answer

Mass is a measure of the amount of matter in an object, which does not depend on the object's location or the force acting upon it.

Question 7

As two clear liquid solutions are thoroughly mixed, a red solid forms. This change is most likely _____ .
A)physical.
B)chemical.
C)neither chemical nor physical.
D)both chemical and physical.

Accepted Answer

The formation of a red solid from the mixing of two clear liquid solutions indicates a chemical change, as new substances are being formed.

Question 8

Any two objects are attracted to each other by _____ .
A)gravity
B)electrostatic forces
C)magnetism
D)all of them

Accepted Answer

Gravity is the universal force that attracts any two objects with mass towards each other.

Question 9

Table salt, NaCl is best classified as a(n)_____ .
A)compound
B)element
C)homogeneous mixture
D)heterogeneous mixture

Accepted Answer

Table salt (NaCl) is a compound because it consists of two or more elements (sodium and chlorine) chemically combined in a fixed ratio.

Question 10

The limit of chemical subdivision of an element is the _____ .
A)atom
B)molecule
C)proton
D)compound

Accepted Answer

The atom is the smallest unit of an element that retains the chemical properties of that element, making it the limit of chemical subdivision.

Question 11

The limit of physical subdivision of pure H₂O is _____ . A)the atom B)the molecule C)the element D)a proton

Accepted Answer

The smallest unit of water (H2O) that retains its chemical properties is the molecule.

Question 12

How is the weight of an object influenced when the gravitational force on the object is increased?
A)it decreases
B)it increases
C)it is unchanged
D)it equals the mass

Accepted Answer

When the gravitational force on an object increases, its weight increases because weight is directly proportional to the gravitational force acting on the object.

Question 13

Which of the following is a chemical property of matter?
A)color
B)density
C)freezing point
D)flammability

Accepted Answer

Flammability is a chemical property because it describes a substance's ability to undergo a chemical change by reacting with oxygen to produce heat and light.

Question 14

Two pure substances A and B react to form a new pure substance C. From this, we may conclude that
A)A and B are both elements
B)C is a compound, A and B may or may not be elements
C)C is an element, A and B are compounds
D)A, B, and C are all compounds

Accepted Answer

When two pure substances react to form a new pure substance, the product is a compound, and the reactants can be either elements or compounds. This is because a compound is defined as a substance formed when two or more chemical elements are chemically bonded together. The initial substances (A and B) could be elements combining to form a compound, or they could be compounds reacting to form a new compound.

Question 15

After heating, a pure substance, A, is found to produce both B and C. What can be said about the substance A?
A)It is an element
B)It is a compound
C)It is either an element or compound
D)Impossible to predict

Accepted Answer

A pure substance that produces more than one type of substance upon heating is a compound, as elements cannot be broken down into simpler substances by chemical means.

Question 16

The weight of an object is
A)a measure of the gravitational force pulling the object toward the earth.
B)equal to the mass of the matter in the object.
C)a measure of the space occupied by the object.
D)the same at any location on the earth.

Accepted Answer

Weight is the force exerted by gravity on an object, which varies depending on the object's mass and the gravitational pull at its location.

Question 17

Which of the following terms correctly applies to a molecule of CO₂? A)triatomic, heteroatomic B)polyatomic, diatomic C)triatomic, homoatomic D)diatomic, heteroatomic

Accepted Answer

The molecule COS consists of three different atoms (carbon, oxygen, and sulfur), making it triatomic because it has three atoms, and heteroatomic because those atoms are not all the same element.

Question 18

The melting of ice to liquid water is correctly classified as
A)a chemical change.
B)a physical change.
C)both a chemical and a physical change.
D)neither a chemical nor physical change.

Accepted Answer

The melting of ice to liquid water is a physical change because it involves a change in the state of matter (from solid to liquid) without altering the chemical composition of the substance.

Question 19

The fact that gold does not corrode is a ______ property
A)physical
B)personal
C)real
D)chemical

Accepted Answer

The fact that gold does not corrode is a chemical property because it relates to how gold reacts (or does not react) with its environment, specifically its resistance to oxidation and corrosion.

Question 20

Which of the following substances are composed of heteroatomic molecules?
A)an iron nail
B)oxygen
C)copper wire
D)water

Accepted Answer

Water is composed of heteroatomic molecules, as it consists of different types of atoms (hydrogen and oxygen) bonded together.

Quiz 1: Matter, Measurements, and Calculations

A molecule represented by O-O-O must be classified as

Which of the following represents a physical change in matter?

Which of the following is a physical property of matter?

Which of the following is an example of a homogeneous mixture?

Homoatomic pure substances are known as _____ .

The mass of an object is

As two clear liquid solutions are thoroughly mixed, a red solid forms. This change is most likely _____ .

Any two objects are attracted to each other by _____ .

Table salt, NaCl is best classified as a(n) _____ .

The limit of chemical subdivision of an element is the _____ .

The limit of physical subdivision of pure H₂O is _____ .

How is the weight of an object influenced when the gravitational force on the object is increased?

Which of the following is a chemical property of matter?

Two pure substances A and B react to form a new pure substance C. From this, we may conclude that

After heating, a pure substance, A, is found to produce both B and C. What can be said about the substance A?

The weight of an object is

Which of the following terms correctly applies to a molecule of CO₂?

The melting of ice to liquid water is correctly classified as

The fact that gold does not corrode is a ______ property

Which of the following substances are composed of heteroatomic molecules?