An element has an electronic configuration of $2, 8, 18, 1$. If its atomic weight is $63$,then how many neutrons will be present in its nucleus?

The number of protons,neutrons and electrons in the ion ${ }_{16}^{32} S^{2-}$ respectively are

The atoms $_6C^{13}$ and $_8O^{17}$ are related to each other as .......

Write the complete symbol for the atom with the given atomic number $(Z)$ and atomic mass $(A)$:
$(i)$ $\quad Z=17, A=35$
$(ii)$ $\quad Z=92, A=233$
$(iii)$ $\quad Z=4, A=9$

The chlorine atom differs from the chloride ion in the number of:

If the number of neutrons in $_{8}O^{16}$ is doubled and the number of electrons is halved,what is the percentage change in its mass?