Explain the following with one example of each:
$(i)$ Atomic number
$(ii)$ Mass number

(N/A) $(i)$ Atomic number: It is defined as the total number of protons present in the nucleus of an atom and is denoted by the symbol $Z$. For example,the atomic number of Carbon $(C)$ is $6$,which means it has $6$ protons in its nucleus.
$(ii)$ Mass number: It is defined as the sum of the total number of protons and neutrons present in the nucleus of an atom. It is denoted by the symbol $A$. For example,a Nitrogen $(N)$ atom has $7$ protons and $7$ neutrons,so its mass number is $7 + 7 = 14$.