Rutherford's alpha $(\alpha)$ particles scattering experiment resulted in the discovery of:

Complete the table on the basis of information available in the symbols given below:
$(a)$ ${ }_{17}^{35} Cl$
$(b)$ ${ }_{6}^{12} C$
$(c)$ ${ }_{35}^{81} Br$

Element	$n_{(p)}$	$n_{(n)}$

Identify the $Mg^{2+}$ ion from the figures,where $n$ and $p$ represent the number of neutrons and protons,respectively.

Will $^{35}Cl$ and $^{37}Cl$ have different valencies? Justify your answer.

The number of electrons in an element $X$ is $15$ and the number of neutrons is $16$. Which of the following is the correct representation of the element?

State whether the following statement is true or false:
The relative atomic masses of all elements have been found with respect to an atom of oxygen-$16$.