Ionic bonds between Na\textsuperscript{+} and Cl\textsuperscript{--} ions

Question 1

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds keep water molecules farther apart in a solid state.

Question 2

Which property of water allows it to dissolve many ionic and polar substances?

Accepted Answer

Water's polarity enables it to surround and separate charged and polar molecules, forming aqueous solutions.

Question 3

A scientist mixes sodium chloride (NaCl) in water. Which type of bond is broken when NaCl dissolves?

Accepted Answer

Ionic bonds between Na	extsuperscript{+} and Cl	extsuperscript{--} ions

Question 4

Which of the following statements about chemical reactions is correct?

Accepted Answer

Chemical reactions rearrange atoms by breaking and forming bonds, but do not create or destroy matter.

Question 5

What is the main reason water has a high surface tension?

Accepted Answer

Cohesion due to hydrogen bonding between water molecules

Question 6

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with the same number of protons but different numbers of neutrons

Question 7

A molecule of water (H$$_2O) is $$held together by which type of bond?

Accepted Answer

Polar covalent bonds between hydrogen and oxygen

Question 8

Which of the following is an example of an emergent property?

Accepted Answer

Table salt (NaCl) has properties different from both sodium and chlorine.

Question 9

What happens to the temperature of water as it evaporates from your skin?

Accepted Answer

The surface cools due to evaporative cooling as the most energetic molecules leave.

Question 10

Which statement best describes the difference between cohesion and adhesion?

Accepted Answer

Cohesion is the attraction between molecules of the same kind; adhesion is the attraction between different kinds of molecules.

Question 11

Which of the following best describes a compound?

Accepted Answer

A substance consisting of two or more different elements in a fixed ratio

Question 12

What is the atomic number of an element?

Accepted Answer

The number of protons in the nucleus

Question 13

Which of the following is true about hydrogen bonds?

Accepted Answer

They are weak bonds formed between a hydrogen atom and an electronegative atom like oxygen.

Question 14

Which scenario best illustrates the concept of surface tension?

Accepted Answer

A water strider insect walking on the surface of a pond without sinking

Question 15

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its mass number?

Accepted Answer

$$16$$

Question 16

Which of the following is a result of water's high specific heat?

Accepted Answer

Water helps moderate temperature changes in the environment.

Question 17

Which of the following best describes a nonpolar covalent bond?

Accepted Answer

Electrons are shared equally between two atoms.

Question 18

What is the main difference between an ion and an atom?

Accepted Answer

An ion has an electrical charge due to the gain or loss of electrons.

Question 19

Which of the following is an example of a chemical reaction?

Accepted Answer

The formation of water from hydrogen and oxygen gases

Question 20

Why does water have a high heat of vaporization?

Accepted Answer

Because hydrogen bonds must be broken for water molecules to evaporate

The Chemical Basis of Life: Elements, Atoms, and Water

Study Guide - Practice Questions