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

$$\text{Atomic number} = \text{Number of protons}$$

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

Question 1

Which of the following best describes a chemical element?

Accepted Answer

A pure substance made of only one type of atom.

Question 2

What is the correct formula to calculate the number of neutrons in an atom?

Accepted Answer

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

Question 3

An atom of oxygen has an atomic number of 8 and a mass number of 16. How many neutrons does it have?

Accepted Answer

8

Question 4

Which subatomic particle is found in the nucleus and has no electric charge?

Accepted Answer

Neutron

Question 5

According to the periodic table, which elements make up approximately 97% of the mass of most life forms?

Accepted Answer

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur

Question 6

Which of the following statements about electron energy shells is TRUE?

Accepted Answer

Shells closer to the nucleus are lower in energy than shells farther away.

Question 7

How many valence electrons does a nitrogen atom (atomic number 7) have?

Accepted Answer

5

Question 8

Which rule states that atoms are more stable when their valence shells are fully occupied?

Accepted Answer

Octet Rule

Question 9

A neon atom is unreactive because:

Accepted Answer

Its valence shell is full of electrons.

Question 10

How many electrons does an oxygen atom need to fulfill the octet rule by filling its valence shell?

Accepted Answer

2

Question 11

Which of the following is the correct relationship for atomic number?

Accepted Answer

$$	ext{Atomic number} = 	ext{Number of protons}$$

Question 12

Which of the following is NOT a subatomic particle found in atoms?

Accepted Answer

Polymer

Question 13

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

Accepted Answer

$$6 + 6 = 12$$

Question 14

Which of the following best explains why trace elements are important in living organisms?

Accepted Answer

They are required in small amounts for essential biological processes.

Question 15

Which of the following is true about valence electrons?

Accepted Answer

They are found in the outermost energy shell of an atom.

Question 16

If the first energy shell of an atom holds up to 2 electrons, how many electrons can the second energy shell hold?

Accepted Answer

8

Question 17

Which of the following is a correct statement about the periodic table?

Accepted Answer

It arranges elements based on their chemical properties.

Question 18

Which of the following atoms is most likely to form bonds to achieve a full valence shell?

Accepted Answer

Oxygen

Question 19

Which of the following is the correct formula for calculating the total mass number of an atom?

Accepted Answer

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

Question 20

Which of the following is a real-world example of a molecule composed of only one type of chemical element?

Accepted Answer

Diamond (pure carbon)

Atomic Structure and Elements: Foundations for Anatomy & Physiology

Study Guide - Practice Questions