Define isotopes,isobars,and isotones.

(N/A) $1$. Isotopes: Atoms of the same element that have the same atomic number $(Z)$ but different mass numbers $(A)$. They have the same number of protons but a different number of neutrons. Example: $^1_1H, ^2_1H, ^3_1H$.
$2$. Isobars: Atoms of different elements that have the same mass number $(A)$ but different atomic numbers $(Z)$. Example: $^{40}_{18}Ar$ and $^{40}_{20}Ca$.
$3$. Isotones: Atoms of different elements that have the same number of neutrons $(N = A - Z)$. Example: $^{14}_6C$ and $^{15}_7N$ both have $8$ neutrons.