Question

An ion carries the charge of $X^{3-}$, then the number of electrons in its valence shell is _____ .

• A. 3
• B. 5
• C. 6
• D. 7

Answer 1

Answer: (B)

5

An ion carries the charge of $X^{3-}$, then the number of electrons in its valence shell is 5. It has gained 3 electrons to complete its octet. Number of electrons gained is equal to the charge on the anion. The number of valence electrons is equal to 8 minus the charge on the ion.

$8-3=5$