Question 1

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 2

Which statement about electron shells is correct?

Accepted Answer

The first shell can hold up to 2 electrons.

Question 3

A neutral atom of sodium (Na) has an atomic number of 11 and a mass number of 23. How many neutrons does it have?

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 4

Which of the following best explains why noble gases are generally unreactive?

Accepted Answer

They have a full valence shell of electrons.

Question 5

What type of bond is formed when two atoms share electrons equally?

Accepted Answer

Nonpolar covalent bond

Question 6

Which of the following is a real-world example of a hydrogen bond?

Accepted Answer

The attraction between water molecules.

Question 7

If an atom has 8 protons, 8 neutrons, and 10 electrons, what is its charge?

Accepted Answer

2-

Question 8

Which of the following best describes a polar covalent bond?

Accepted Answer

A bond where electrons are shared unequally between atoms.

Question 9

What is the maximum number of electrons that can occupy the second electron shell?

Accepted Answer

8

Question 10

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons determine the chemical behavior of an atom.

Question 11

Which of the following best explains why water is a polar molecule?

Accepted Answer

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

Question 12

Which type of bond is responsible for the unique properties of water, such as high surface tension and cohesion?

Accepted Answer

Hydrogen bonds

Question 13

A chlorine atom has 17 protons and 18 neutrons. What is its mass number?

Accepted Answer

$$17 + 18 = 35$$

Question 14

Which of the following is true about ionic bonds?

Accepted Answer

They result from the attraction between oppositely charged ions.

Question 15

Which of the following best describes potential energy in an atom?

Accepted Answer

The energy an electron has due to its position relative to the nucleus.

Question 16

Which of the following is a correct Lewis structure for a water molecule ($$H_2O$$)?

Accepted Answer

O with two single bonds to H and two lone pairs on O

Question 17

Which of the following is an example of a molecule held together by nonpolar covalent bonds?

Accepted Answer

$$O_2$$

Question 18

Which of the following best explains why sodium (Na) forms an ionic bond with chlorine (Cl)?

Accepted Answer

Sodium donates an electron to chlorine, resulting in oppositely charged ions.

Question 19

Which of the following is a property of hydrogen bonds that is important for life?

Accepted Answer

They allow water to remain liquid at a wide range of temperatures.

Question 20

Which of the following best describes the relationship between atomic number and the number of protons in an atom?

Accepted Answer

The atomic number is equal to the number of protons.

The Chemical Context of Life: Study Guide and Review

Study Guide - Practice Questions