Question

The number of protons, neutrons and electrons in ${}_{15}^{31}{P}^{3-}$ respectively, are:

• A. 15, 18 and 16
• B. 15, 16 and 18
• C. 16, 15 and 18
• D. 18, 16 and 15

Answer 1

The correct option is B 15, 16 and 18

${}_{15}^{31}{P}^{3-}:\text{Number of protons =15}$
Number of neutrons $=31-15=16$
Number of electrons $=15+3=18$