E = m c²
where E = energy released
m = mass of the nucleus
C= velocity of light
m = 9.106 x 10⁻³ x 1.67 x 10⁻²⁷ kg
C = 3 x 10⁸ m/s and C² = 9 x 10¹⁶
E = 1.37 x 10 ⁻¹² J
Fluorine and other halogens are diatomic in nature which means atoms should be paired to each other so as to exist in nature. Generally, diatomic halogens exist as gas to the exception of iodine because of its large molecular weight. Iodine exists as liquid at room temperature and pressure.