Atomic number means

The isobars are atoms with the same number of

An element has an atomic mass of $19$ and an atomic number of $9$. How can its ion be represented?

The specific charge of a proton is $9.6 \times 10^7 \ C \ kg^{-1}$. What will be the specific charge for an $\alpha$-particle?

When $\mathop a\limits^x U$ is converted into $\mathop b\limits^y P$,which of the following represents the correct decrease in the number of neutrons?

The electronic configuration of a dipositive metal $M^{2+}$ is $2, 8, 14$ and its atomic weight is $56 \ a.m.u.$ The number of neutrons in its nuclei would be