Question

If the number of protons in $X^{2-}$ is 16, then the number of electrons in $X^{2+}$ will be:

• A. 14
• B. 16
• C. 18
• D. Cannot be determined

Answer 1

The correct option is A 14

Given:
Number of protons in $X^{2-}$ = 16
Number of protons remains constant.
In a neutral species,
Number of protons = number of electrons
Four electrons are removed from $X^{2-}$ to form $X^{2+}$ and therefore the number of electrons in $X^{2+}$ is
$=\text{Number of electrons in}{X}^{2-}-\text{Number of electrons lost/removed}$
$=18-4$
$=14$