Question 1

Which of the following best explains why questions about life are fundamentally questions about chemistry?

Accepted Answer

Because all living organisms are composed of matter, and their functions depend on chemical interactions.

Question 2

Which four elements make up approximately 96% of the mass of living organisms?

Accepted Answer

Carbon, hydrogen, oxygen, and nitrogen

Question 3

A nitrogen atom has 7 protons. Its most common isotope has 7 neutrons, but a radioactive isotope has 9 neutrons. What are the atomic number and mass number of this radioisotope?

Accepted Answer

Atomic number: 7, Mass number: 16

Question 4

Which statement best describes why helium, neon, and argon are chemically inert?

Accepted Answer

Their outermost electron shells are full, making them stable and unreactive.

Question 5

How many covalent bonds can a nitrogen atom typically form, based on the octet rule?

Accepted Answer

3

Question 6

Which of the following best explains why water molecules are polar?

Accepted Answer

Oxygen is more electronegative than hydrogen, causing unequal sharing of electrons.

Question 7

What holds together the ions in a crystal of table salt (NaCl)?

Accepted Answer

Electrostatic attraction between oppositely charged ions

Question 8

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom in one molecule and an electronegative atom in another molecule

Question 9

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds keep water molecules in ice farther apart, making it less dense than liquid water.

Question 10

If the pH of a solution changes from 9 to 4, how many times more acidic is the solution at pH 4 compared to pH 9?

Accepted Answer

$$10^5$$

Question 11

Which property of water allows it to moderate Earth's climate and body temperature?

Accepted Answer

High specific heat due to hydrogen bonding

Question 12

Which of the following best defines a buffer in biological systems?

Accepted Answer

A substance that minimizes changes in pH by accepting or donating H$$^+$$ ions

Question 13

Which of the following best explains why sweating cools the body?

Accepted Answer

Evaporation of sweat absorbs heat energy due to water's high heat of vaporization

Question 14

Which of the following is an example of an ionic bond?

Accepted Answer

The bond between sodium and chlorine in NaCl

Question 15

A solution is made by dissolving glucose (C$$_6H$_{12}O$_6) in $$water. Which term best describes water in this scenario?

Accepted Answer

Solvent

Question 16

Which of the following best describes why non-ionic compounds like glucose can dissolve in water?

Accepted Answer

They form hydrogen bonds with water molecules due to their polar regions.

Question 17

Which of the following statements about chemical reactions is correct?

Accepted Answer

Reactants are transformed into products through the breaking and forming of chemical bonds.

Question 18

Which property of water explains why beads of sweat form on your skin after exercise?

Accepted Answer

Cohesion and surface tension due to hydrogen bonding

Question 19

What would be the consequence for aquatic life if ice sank instead of floated?

Accepted Answer

Bodies of water would freeze solid from the bottom up, threatening aquatic life.

Question 20

How does water moderate global climate?

Accepted Answer

By absorbing and releasing heat slowly due to its high specific heat

Guided Study for Chemistry Foundations in Biology (Chapter 2)

Study Guide - Practice Questions

Study Guide - Flashcards