$$\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}$$

Question 1

Which of the following statements best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons.

Question 2

Which of the following best explains why carbon-14 is radioactive while carbon-12 is not?

Accepted Answer

Carbon-14 has more neutrons, making its nucleus unstable and prone to decay.

Question 3

Which of the following is the correct formula for calculating the number of neutrons in an atom?

Accepted Answer

$$	ext{Number of neutrons} = 	ext{Mass number} - 	ext{Atomic number}$$

Question 4

Which property of an atom determines its chemical behavior?

Accepted Answer

The number of electrons in its outermost shell.

Question 5

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from one atom to another.

Question 6

What is the main difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

A polar covalent bond involves unequal sharing of electrons, while a nonpolar covalent bond involves equal sharing.

Question 7

Which of the following elements is most likely to form a triple covalent bond?

Accepted Answer

Nitrogen ($$N_2)$$

Question 8

Which of the following is a real-world application of radioactive isotopes?

Accepted Answer

Dating ancient fossils using carbon-14.

Question 9

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number = 8, Mass number = 16

Question 10

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

Accepted Answer

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

Question 11

Which of the following statements about electrons is correct?

Accepted Answer

Electrons occupy energy levels, with those farther from the nucleus having higher energy.

Question 12

Which of the following best describes the relationship between atomic number and the identity of an element?

Accepted Answer

The atomic number is equal to the number of protons, which defines the element.

Question 13

Which of the following is a characteristic of a polar molecule?

Accepted Answer

It has regions of partial positive and partial negative charge due to unequal sharing of electrons.

Question 14

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

Accepted Answer

They have a full valence electron shell.

Question 15

Which of the following is the correct order of the chemistry progression from smallest to largest?

Accepted Answer

Atoms $$\rightarrow$$ Molecules $$\rightarrow$$ Chemical Bonds $$\rightarrow$$ Biology & Life

Question 16

Which of the following is a multidisciplinary aspect of biology?

Accepted Answer

It integrates concepts from chemistry and physics to explain biological processes.

Question 17

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

Accepted Answer

A molecule consists of two or more atoms bonded together, while a compound consists of two or more different elements bonded together.

Question 18

Which of the following is the best example of a nonpolar covalent bond?

Accepted Answer

The bond between two hydrogen atoms in $$H_2$$

Question 19

Which of the following best explains why water ($$H_2O) is a $$polar molecule?

Accepted Answer

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

Atomic Theory and Chemical Bonds: Foundations for Biology

Study Guide - Practice Questions