Chapter 7, Problem 86A

(a)

Interpretation Introduction

Interpretation: Each element in the following list is to be classified as a cation or anion or element that is chemically nonreactive. The number of electrons the atom will gain or lose is to be written.

Concept Introduction: An atom is electrically neutral because it contains equal amounts of protons and electrons. When an atom or collection of atoms loses or receives electrons, an ion is created.

Answer to Problem 86A

Lithium is a cation.

There is a loss of one electron during the chemical reaction.

Explanation of Solution

A cation, or positively charged ion, is created when an atom loses its valence electrons.

Lithium belongs to group 1A elements. It loses an electron to form a lithium cation $\left({\text{Li}}^{\text{+}}\right)$ .

  $\text{Li}\left(1s^{2}2s^1\right)\stackrel{-{\text{e}}^{-}}{\to }{\text{Li}}^{\text{+}}\left(1s^2\right)$

Lithium loses one electron during a chemical reaction in order to form an ion.

(b)

Interpretation Introduction

Interpretation: Each element in the following list is to be classified as a cation or anion or element that is chemically nonreactive. The number of electrons the atom will gain or lose is to be written.

Concept Introduction: An atom is electrically neutral because it contains equal amounts of protons and electrons. When an atom or collection of atoms loses or receives electrons, an ion is created.

Answer to Problem 86A

Sodium is a cation.

There is a loss of one electron during the chemical reaction.

Explanation of Solution

A cation, or positively charged ion, is created when an atom loses its valence electrons.

Sodium belongs to group 1A elements. It loses an electron to form a sodium cation $\left({\text{Na}}^{\text{+}}\right)$ .

  $\text{Na}\left(1s^{2}2s^{2}2p^{6}3s^1\right)\stackrel{-{\text{e}}^{-}}{\to }{\text{Na}}^{\text{+}}\left(1s^{2}2s^{2}2p^6\right)$

Sodium loses one electron during a chemical reaction in order to form an ion.

(c)

Interpretation Introduction

Interpretation: Each element in the following list is to be classified as a cation or anion or element that is chemically nonreactive. The number of electrons the atom will gain or lose is to be written.

Concept Introduction: An atom is electrically neutral because it contains equal amounts of protons and electrons. When an atom or collection of atoms loses or receives electrons, an ion is created.

Answer to Problem 86A

Neon is a chemically unreactive element.

Explanation of Solution

A cation, or positively charged ion, is created when an atom loses its valence electrons.

An anion is created when a neutral atom accepts extra negatively charged electrons.

Neon is a noble gas that has an octet configuration. There is neither loss nor gain of electrons.

Due to octet configuration, it is unreactive in a chemical reaction.

(d)

Interpretation Introduction

Interpretation: Each element in the following list is to be classified as a cation or anion or element that is chemically nonreactive. The number of electrons the atom will gain or lose is to be written.

Concept Introduction: An atom is electrically neutral because it contains equal amounts of protons and electrons. When an atom or collection of atoms loses or receives electrons, an ion is created.

Answer to Problem 86A

Chlorine is an anion.

There is a gain of one electron during the chemical reaction.

Explanation of Solution

An anion is created when a neutral atom accepts extra negatively charged electrons.

Chlorine belongs to group 7A elements. It gains an electron to form a chloride anion $\left({\text{Cl}}^{-}\right)$ .

  $\text{Cl}\left(1s^{2}2s^{2}2p^{6}3s^{2}3p^5\right)\stackrel{{\text{+e}}^{-}}{\to }{\text{Cl}}^{-}\left(1s^{2}2s^{2}2p^{6}3s^{2}3p^6\right)$

Chlorine gains one electron during a chemical reaction in order to form an ion.

(e)

Interpretation Introduction

Interpretation: Each element in the following list is to be classified as a cation or anion or element that is chemically nonreactive. The number of electrons the atom will gain or lose is to be written.

Concept Introduction: An atom is electrically neutral because it contains equal amounts of protons and electrons. When an atom or collection of atoms loses or receives electrons, an ion is created.

Answer to Problem 86A

Magnesium is a cation.

There is a loss of two electrons during the chemical reaction.

Explanation of Solution

A cation, or positively charged ion, is created when an atom loses its valence electrons.

Magnesium belongs to group 2A elements. It loses two electrons to form a magnesium cation $\left({\text{Mg}}^{\text{2+}}\right)$ .

  $\text{Mg}\left(1s^{2}2s^{2}2p^{6}3s^2\right)\stackrel{-2{\text{e}}^{-}}{\to }{\text{Mg}}^{2+}\left(1s^{2}2s^{2}2p^6\right)$

Magnesium loses two electrons during a chemical reaction in order to form an ion.