Question

If a species has 16 protons, 18 electrons and 16 neutrons, the symbol (with charge) of species is:

• A. $S^{-}$
• B. ${Si}^{2-}$
• C. $P^{3-}$
• D. $S^{2-}$

Answer 1

The correct option is D $S^{2-}$

The species has 16 protons and 16 neutrons, which means its mass number is 32. Hence the element we are talking about is Sulphur, which is represented by the symbol $S$.
As we can see that that the number of protons is less than electrons, it means that the species will have a negative charge over it. Also, there are two excess electrons, hence the magnitude of the negative charge would be $2$.
The species will be represented by $S^{2-}$