Question 1

Which of the following statements best explains why atoms are considered the fundamental building blocks of matter?

Accepted Answer

Atoms are the smallest units of matter that retain the chemical properties of an element.

Question 2

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

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 3

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 4

Which subatomic particle is responsible for the chemical behavior of an atom?

Accepted Answer

Electrons

Question 5

What is the maximum number of electrons that can occupy a single orbital?

Accepted Answer

$$2$$ electrons

Question 6

Which of the following best explains why sodium (Na) and chlorine (Cl) form an ionic bond in table salt (NaCl)?

Accepted Answer

Sodium donates an electron to chlorine, resulting in oppositely charged ions that attract each other.

Question 7

Which of the following is true about covalent bonds?

Accepted Answer

They involve the sharing of electron pairs between atoms.

Question 8

A molecule of water (H$$_2O) is $$held together by which type of bond, and what type of bond forms between different water molecules?

Accepted Answer

Covalent bonds within the molecule; hydrogen bonds between molecules

Question 9

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Question 10

Which of the following elements is most abundant in living organisms?

Accepted Answer

Oxygen

Question 11

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

Accepted Answer

Oxygen is more electronegative than hydrogen, creating partial charges.

Question 12

Which of the following is a correct statement about energy levels and electron transitions?

Accepted Answer

Electrons absorb energy to move to higher energy levels and release energy when returning to lower levels.

Question 13

Which of the following best describes a cation?

Accepted Answer

An atom that has lost one or more electrons and has a positive charge

Question 14

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

They are weak bonds that form between polar molecules, such as water.

Question 15

Which of the following best explains why noble gases like neon (Ne) are chemically inert?

Accepted Answer

Their valence shells are completely filled with electrons.

Question 16

Which of the following is the correct electron configuration for a neutral carbon atom (atomic number 6)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^2$$

Question 17

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

Accepted Answer

A molecule is a group of atoms held together by energy, while a compound contains atoms of more than one element.

Question 18

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

Accepted Answer

The polar water molecules surround and separate the Na$$^+$$ and Cl$$^-$$ ions.

Question 19

Which of the following is the strongest type of chemical bond found in biological molecules?

Accepted Answer

Covalent bond

Question 20

A patient is exposed to a radioactive isotope of carbon, carbon-14. Which of the following is true about carbon-14 compared to carbon-12?

Accepted Answer

Carbon-14 has two more neutrons than carbon-12.

The Chemical Context of Life: Atoms, Elements, and Chemical Bonds

Study Guide - Practice Questions