Question 1

Which of the following best describes an element?

Accepted Answer

A substance that cannot be broken down to other substances by chemical reactions.

Question 2

Which statement about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 3

Given the atomic number and atomic mass of carbon are 6 and 12.01, respectively, how many neutrons are in the most common isotope of carbon?

Accepted Answer

$$12 - 6 = 6$$ neutrons

Question 4

Which of the following best explains why table salt (NaCl) dissolves easily in water?

Accepted Answer

NaCl is an ionic compound, and water molecules surround and separate the ions.

Question 5

Which of the following statements about covalent bonds is correct?

Accepted Answer

Covalent bonds involve the sharing of pairs of valence electrons between atoms.

Question 6

A water molecule ($$\mathrm{H_2O}) is $$held together by which type of bonds, and what property does this give water?

Accepted Answer

Polar covalent bonds; gives water partial positive and negative charges.

Question 7

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 8

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

Accepted Answer

The ability of sodium and chlorine to form a compound with properties different from the individual elements.

Question 9

Which of the following best explains why noble gases are chemically inert?

Accepted Answer

They have a full valence shell of electrons.

Question 10

Which of the following equations correctly represents the reversible dissociation of nitrous acid ($$\mathrm{$$HNO_2$$}) in $$water?

Accepted Answer

$$\mathrm{$$HNO_2$$} \rightleftharpoons \mathrm{H^+} + \mathrm{NO_2$^-}$$

Question 11

Which of the following best describes chemical equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate, and the concentrations of reactants and products remain constant.

Question 12

Which of the following is true about van der Waals interactions?

Accepted Answer

They are weak attractions that occur when electrons are distributed asymmetrically in molecules.

Question 13

Which of the following best explains why morphine and endorphins can both bind to the same receptors in the brain?

Accepted Answer

They have similar molecular shapes that fit the receptor.

Question 14

Which of the following is a real-life example of a chemical reaction important for life?

Accepted Answer

Photosynthesis: $$6\mathrm{CO_2$} + 6\mathrm{H_2O} \rightarrow \mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$}$$

Question 15

Which of the following statements about potential energy is correct?

Accepted Answer

Potential energy is the energy that matter possesses because of its location or structure.

Question 16

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule consists of two or more atoms held together by covalent bonds, while a compound consists of two or more different elements in a fixed ratio.

Question 17

Which of the following is true about the chemical behavior of an atom?

Accepted Answer

It is mostly determined by the number of valence electrons.

Question 18

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from one atom to another, resulting in oppositely charged ions.

Question 19

Which of the following is a property of a polar covalent bond?

Accepted Answer

One atom is more electronegative, causing unequal sharing of electrons.

Question 20

Which of the following is true about chemical reactions?

Accepted Answer

They involve the making and breaking of chemical bonds.

The Chemical Context of Life (Campbell Biology, Ch. 2): Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards