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

$$\text{Atomic mass} = \text{Number of protons} + \text{Number of neutrons}$$

Question 1

Which of the following statements best describes a chemical element?

Accepted Answer

A pure substance made of only one type of atom.

Question 2

Which subatomic particle determines the atomic number of an element?

Accepted Answer

Proton

Question 3

Given an oxygen atom with a mass number of 16 and an atomic number of 8, how many neutrons does it have?

Accepted Answer

$$8$$

Question 4

Which of the following elements is NOT one of the six most common elements in living organisms (CHNOPS)?

Accepted Answer

Calcium

Question 5

What is the total number of electrons in a neutral carbon atom?

Accepted Answer

$$6$$

Question 6

Which of the following best explains why neon (Ne) is chemically unreactive?

Accepted Answer

Its valence shell is full.

Question 7

According to the octet rule, how many electrons does an oxygen atom need to gain to fill its valence shell?

Accepted Answer

$$2$$

Question 8

Which statement is TRUE about isotopes of an element?

Accepted Answer

They have the same atomic number but different mass numbers.

Question 9

How are Carbon-13 and Nitrogen-15 isotopes different from the more abundant Carbon-12 and Nitrogen-14?

Accepted Answer

Each has one extra neutron.

Question 10

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

Accepted Answer

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

Question 11

Which of the following is a use of radioactive isotopes in medicine?

Accepted Answer

Labeling regions of the body for special imaging techniques.

Question 12

If the half-life of Carbon-14 is 5,730 years, how many years must pass for a sample to decay to $$\frac{1}{4} of $$its original amount?

Accepted Answer

$$11,460$$

Question 13

Which of the following statements about electron shells is TRUE?

Accepted Answer

Valence electrons are found in the outermost shell.

Question 14

What is the maximum number of electrons that can be held in the first energy shell of an atom?

Accepted Answer

$$2$$

Question 15

Which of the following is the correct definition of a cation?

Accepted Answer

An atom that has lost electrons and has a positive charge.

Question 16

Which of the following is the correct chemical formula for glucose?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$

Question 17

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak interaction between a hydrogen atom and a highly electronegative atom such as oxygen or nitrogen.

Question 18

Which of the following is TRUE about the periodic table?

Accepted Answer

It arranges elements based on their chemical properties.

Question 19

Which of the following is a trace element required for life in small amounts?

Accepted Answer

Iron (Fe)

Question 20

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

Accepted Answer

$$	ext{Atomic mass} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Atoms, Elements, and Atomic Structure: General Chemistry Study Notes

Study Guide - Practice Questions