Question

In the symbol He, the superscript 4 is the for helium, and the subscript 2 is the for helium.

Answer 1

subscript is atomic number
superscript is for molecular no or mass

Answer 2

\[_Z^A\text{E}_N^{Q}\]
\(Z\) for the number of protons
\(N\) for the number of neutrons
\(A\) for all the nucleons; i.e. the number of neutrons plus the number of protons
\(Q\) for the charge; ie number of protons minus the number of electrons