Question

From the symbol ${}_{16}{}^{32}\mathrm{S}$ give :

(b) Mass number of sulphur.

Answer 1

Mass Number:

Mass number of an element is equal to the sum of number of protons and the number of neutrons in an atom of element.

Mass number of Sulphur:

1. The general representation of an element is ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$, where $\mathrm{X}$ is the chemical symbol of an element, $\mathrm{A}$ is the mass number and $\mathrm{Z}$ is the atomic number.
2. Comparing the symbol ${}_{16}{}^{32}\mathrm{S}$ with ${}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}$, $\mathrm{X}=\mathrm{S}$ i.e. Sulphur, $\mathrm{A}=32$ and $\mathrm{Z}=16$.
3. Thus, the mass number of Sulphur is $32$.

Thus, from the symbol ${}_{16}{}^{32}\mathrm{S}$, the mass number of Sulphur is $32$.