In the atom of an element $X$,$6$ electrons are present in the outermost shell. If it acquires noble gas configuration by accepting the requisite number of electrons,what would be the charge on the ion so formed?

Calculate the number of neutrons present in the nucleus of an element $X$ which is represented as $^{31}_{15}X$.

What were the drawbacks of Rutherford's model of an atom?

Write down the electron distribution of chlorine atom. How many electrons are there in the $L$ shell? (Atomic number of chlorine is $17$).

List applications of any three isotopes in various fields.

Answer the following in one line or one word:
$(a)$ Who discovered the neutron?
$(b)$ On the basis of Thomson's model of an atom,explain how the atom is neutral as a whole.
$(c)$ What is the maximum number of electrons that can be accommodated in the outermost shell of an atom?
$(d)$ What term is assigned to the atoms of different elements having the same atomic mass but different atomic numbers?
$(e)$ How many neutrons are present in a hydrogen atom?