If $Z = 3$,what would be the valency of the element? Also,name the element.

If $K$ and $L$ shells of an atom are full,then what would be the total number of electrons in the atom?

Find out the mass number of oxygen and sulphur atoms.

If the number of electrons in an atom is $8$ and the number of protons is also $8$,then $(i)$ what is the atomic number of the atom? and $(ii)$ what is the charge on the atom?

For the symbols $H$,$D$,and $T$,tabulate the number of three sub-atomic particles found in each of them.

If an atom contains one electron and one proton,will it carry any charge or not?