Question

State the number of protons and electrons in each of the following:

a. ${\mathrm{S}}^{2-}$

b. ${\mathrm{Ni}}^{2+}$

c. ${\mathrm{Au}}^{3+}$

d. ${\mathrm{Ag}}^{+}$

Short answer

Part a. $16p,18e$

Part b. $28p,26e$

Part c. $79p,76e$

Part d. $47p,46e$

Step-by-step solution

Part (a) Step 1: Given Information

Electrons are a kind of subatomic molecule with a negative charge. Protons are a sort of subatomic molecule with a positive charge.

Given-$S^{2-}$

Part (a) Step 2: Explanation 

The atomic number of Sulphur is$16$

The number of protons is$16$

Two electrons are gained when$S^{2-}$is formed,

The number of electrons is$16+2=18$

Part (b) Step 1: Given Information

Electrons are a kind of subatomic molecule with a negative charge. Protons are a sort of subatomic molecule with a positive charge.

Given-$N{i}^{2+}$

Part (b) Step 2: Explanation

The atomic number of Nickel is$28$

The number of protons is$28$

Two electrons are lost when$N{i}^{2+}$ is formed,

The number of electrons is$28-2=26$

Part (c) Step 1: Given Information

Electrons are a kind of subatomic molecule with a negative charge. Protons are a sort of subatomic molecule with a positive charge.
Given -$A{u}^{3+}$

Part (c) Step 2: Explanation

The atomic number of gold is$79$

The number of protons is$79$

Three electrons are lost when$A{u}^{3+}$ is formed,

The number of electrons is$79-3=76$

Part (d) Step 1: Given Information

Electrons are a kind of subatomic molecule with a negative charge. Protons are a sort of subatomic molecule with a positive charge.

Given -$A{g}^{+}$

Part (d) Step 2: Explanation

The atomic number of silver is$47$

The number of protons is$47$

One electron is lost when $A{g}^{+}$is formed,

The number of electrons is$47-1=46$