$$\text{Mass number} = \text{Number of protons} + \text{Number of neutrons}$$

Question 1

Which of the following statements correctly describes an ion?

Accepted Answer

An atom with a different number of protons and electrons.

Question 2

Sodium (Na) loses one electron to become Na$$^+. $$What is the resulting charge and why?

Accepted Answer

Positive, because it has more protons than electrons.

Question 3

Which of the following is true about hydrogen ($$^1H$$)?

Accepted Answer

It has one proton and no neutrons.

Question 4

A chlorine ion (Cl$$^-) $$has 17 protons and 18 electrons. What is its charge?

Accepted Answer

Negative

Question 5

Which of the following best describes an isotope?

Accepted Answer

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

Question 6

If an atom has 6 protons, 6 neutrons, and 6 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 6, Mass number: 12

Question 7

Which type of chemical bond involves the sharing of valence electrons between atoms?

Accepted Answer

Covalent bond

Question 8

A molecule of water (H$$_2O) is $$formed by which type of bond between hydrogen and oxygen?

Accepted Answer

Polar covalent bond

Question 9

Which of the following is a correct example of a molecule?

Accepted Answer

H$$_2O$$

Question 10

Which of the following best explains why isotopes of the same element behave similarly in chemical reactions?

Accepted Answer

They have the same number of electrons.

Question 11

A radioactive isotope emits a high-energy particle to become more stable. What is this process called?

Accepted Answer

Radioactive decay

Question 12

Which of the following is NOT a type of covalent bond?

Accepted Answer

Ionic bond

Question 13

If an atom has 11 protons, 12 neutrons, and 10 electrons, what is its net charge?

Accepted Answer

$$+1$$

Question 14

Which of the following best describes a molecule?

Accepted Answer

A group of atoms bonded together.

Question 15

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

Accepted Answer

H$$_2 ($$hydrogen gas)

Question 16

A patient is exposed to a radioactive isotope that emits beta particles. What is the likely effect on the atom’s nucleus?

Accepted Answer

A neutron is converted into a proton.

Question 17

Which of the following equations correctly represents the calculation of mass number?

Accepted Answer

$$	ext{Mass number} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Question 18

Which of the following is true about the stability of atoms?

Accepted Answer

Atoms become more stable by gaining or losing neutrons, which may result in radioactive decay.

Question 19

Which of the following is a correct statement about the relationship between protons and electrons in a cation?

Accepted Answer

A cation has more protons than electrons.

Question 20

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.

Atoms, Ions, Isotopes, and Chemical Bonds: Fundamental Concepts in General Biology

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