Students are advised to answer the question of Mehedi Hasan Himel

When a bond breaks, one of the bonded atoms take both the electrons and become anion. The rest of the molecules become cation. This is known as heterolytic fission. Heterolytic fission will always produce ions. For example,
If H-H breaks down by heterolytic fission & if one of the H atoms take both the bonded electrons, then that H atom will become anion & the other H atom will become cation.

One of the main example of heterolytic fission is the fission of hydrogen chloride molecule which produces hydrogen ion as cation and chloride ion as anion and the reaction can be shown as below.
HCl = H+ + Cl-
Because its electronegativity is stronger than that of hydrogen, the chlorine atom preserves the bond pair of electrons. As a result, the chloride anion and hydrogen cation are generated as products.