$\mathrm{^{24}Mg}$ \text{ and } \mathrm{^{24}Mg^{2+}}$

Question 1

Which of the following best describes how a cation is formed?

Accepted Answer

By losing electrons to achieve a noble gas configuration.

Question 2

A neutral atom of magnesium has 12 protons and 12 neutrons. What is the symbol for the ion formed when this atom loses two electrons?

Accepted Answer

$\mathrm{Mg^{2+}}$

Question 3

Which of the following ions is isoelectronic with $\mathrm{Ne}$?

Accepted Answer

$\mathrm{Na^{+}}$

Question 4

A certain ion has 28 electrons, 35 neutrons, and a mass number of 65. What is the symbol for this ion?

Accepted Answer

$\mathrm{^{65}Cu^{2+}}$

Question 5

Which of the following pairs are both isoelectronic and isotopic?

Accepted Answer

$\mathrm{^{24}Mg}$ 	ext{ and } \mathrm{^{24}Mg^{2+}}$

Question 6

Which of the following ions has 30 neutrons, 21 electrons, and a $+4$ charge?

Accepted Answer

$\mathrm{^{52}Ti^{4+}}$

Question 7

If an atom of boron ($\mathrm{^{11}B}$) gains three electrons, what is the resulting ion's charge?

Accepted Answer

$3-$

Question 8

Which of the following statements about isoelectronic species is correct?

Accepted Answer

Isoelectronic species have the same number of electrons but different numbers of protons.

Question 9

A $\mathrm{Fe^{2+}}$ ion has 26 protons and 24 electrons. What is the net charge of this ion?

Accepted Answer

$+2$

Question 10

Which of the following ions is formed when a neutral sodium atom loses one electron?

Accepted Answer

$\mathrm{Na^{+}}$

Question 11

A neutral atom has 20 protons, 20 neutrons, and 18 electrons. What is the symbol for this ion?

Accepted Answer

$\mathrm{^{40}Ca^{2+}}$

Question 12

Which of the following best explains why $\mathrm{Mg^{2+}}$ and $\mathrm{Na^{+}}$ are isoelectronic?

Accepted Answer

Both ions have the same number of electrons, 10.

Question 13

Which of the following ions has the same number of electrons as $\mathrm{Ar}$?

Accepted Answer

$\mathrm{Ca^{2+}}$

Question 14

A $\mathrm{Cu^{2+}}$ ion has 27 electrons. What is the atomic number of copper?

Accepted Answer

29

Question 15

Which of the following ions is NOT isoelectronic with $\mathrm{Ne}$?

Accepted Answer

$\mathrm{Mg^{+}}$

Ion Formation and Isotopes: Study Notes for Introduction to Chemistry

Study Guide - Practice Questions