Which of the following species contain only $1$ electron?

Fluoride ion $(F^-)$ is isoelectronic with:

An ordinary oxygen sample contains:

Match the following species with their respective number of electrons:
| Species | Number of electrons |
| :--- | :--- |
| $(a)$ $O^{2-}$ | $(i)$ $18$ |
| $(b)$ $Li^{2+}$ | (ii) $2$ |
| $(c)$ $He$ | (iii) $10$ |
| $(d)$ $Ca^{2+}$ | (iv) $1$ |

The number of protons,neutrons and electrons in ${}^{13}_{6}C$ respectively are

Addition of two neutrons in an atom $A$ would