Question 1

Which subatomic particle is responsible for the majority of an atom's mass?

Accepted Answer

Nucleus (protons and neutrons together)

Question 2

What is the charge (in coulombs) of a single proton?

Accepted Answer

$+1.60218 	imes 10^{-19}$ C

Question 3

An atom of calcium-40 ($^{40}_{20}\mathrm{Ca}$) has how many neutrons?

Accepted Answer

20

Question 4

Which statement best explains why atoms of different elements have different chemical properties?

Accepted Answer

They have different numbers of protons.

Question 5

If a potassium atom ($\mathrm{K}$) loses one electron, what is the resulting ion and its charge?

Accepted Answer

$\mathrm{K}^+$, +1$

Question 6

Which of the following is a polyatomic ion?

Accepted Answer

$\mathrm{NH}_4^+$

Question 7

What is the mass number ($A$) of an atom with 17 protons and 18 neutrons?

Accepted Answer

35

Question 8

Which of the following best describes an ionic solid?

Accepted Answer

A solid consisting of oppositely charged ions.

Question 9

A chlorine atom ($\mathrm{Cl}$) gains one electron. What is the resulting ion called?

Accepted Answer

Chloride anion

Question 10

Which of the following ions is NOT a simple ion?

Accepted Answer

$\mathrm{SO}_4^{2-}$

Question 11

Given the reaction $2\mathrm{Na}(s) + \mathrm{Cl}_2(g) \rightarrow 2\mathrm{NaCl}(s)$, what type of compound is formed?

Accepted Answer

Ionic compound

Question 12

Which statement is TRUE about isotopes of an element?

Accepted Answer

They have the same number of protons but different numbers of neutrons.

Question 13

What is the relative charge of a neutron?

Accepted Answer

0

Question 14

Which of the following best describes a cation?

Accepted Answer

A positively charged ion

Question 15

If an atom has 15 protons, 16 neutrons, and 15 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 15, Mass number: 31

Question 16

Which of the following ions is formed when an atom gains electrons?

Accepted Answer

Anion

Question 17

What is the approximate ratio of the mass of a proton to the mass of an electron?

Accepted Answer

1836:1

Question 18

Which of the following is the correct representation for the isotope of calcium with a mass number of 40?

Accepted Answer

$^{40}_{20}\mathrm{Ca}$

Question 19

Which of the following statements about the nucleus of an atom is correct?

Accepted Answer

It contains all the positive charge and most of the mass.

Question 20

A sample contains only $^{31}\mathrm{P}$ atoms. What does this indicate about phosphorus?

Accepted Answer

Phosphorus has only one isotope in nature.

Atoms, Ions, and Ionic Compounds: Structure and Properties

Study Guide - Practice Questions