Question

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

a. $C{u}^{2+}$

b. data-custom-editor="chemistry" ${\mathrm{Se}}^{2-}$

c.$B{r}^{-}$

d.$F{e}^{3+}$

Short answer

Part a. $29$proton, $27$electrons

Part b. $34$protons, $36$electron

Part c. $35$protons, $36$electrons

Part d. $26$protons, $23$electron

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 -$C{u}^{2+}$

Part (a) Step 2: Explanation 

The atomic number of copper = $29$

the number of protons is = $29$

Two electrons are lost when $C{a}^{2+}$is formed,

The number of electrons is = $29-2=27$

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 -$S{e}^{2-}$

Part (b) Step 2: Explanation 

The atomic number of selenium =$34$

the number of protons is =$34$

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

The number of electrons is = $34+2=36$

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 -$B{r}^{-}$

Part (c) Step 2: Explanation 

The atomic number of Bromine = $35$

The number of protons is = $35$

one electron is gained when $B{r}^{-}$is formed,

The number of electrons is = $35+1=36$

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 -$F{e}^{3+}$

Part (d) Step 2: Explanation 

The atomic number of iron = $26$

The number of protons is = $26$

Three electrons are lost when $F{e}^{3+}$is formed,

The number of electrons is = $26-3=23$