What is the fission of covalent bonds?

Which kind of fission is favoured by sunlight?

The major product in the following reaction is

In a reaction,if half of the double bond is broken and two new bonds are formed,this is a case of

Among the given compounds,the correct order of enol content is:
$(I)$ Cyclopentanone
$(II)$ $4$-hydroxycyclopent-$2$-en-$1$-one derivative
$(III)$ $\gamma$-butyrolactone derivative

State True or False for the following statements:
$(i)$ Positive and negative ions are formed by homolytic cleavage of a covalent bond.
$(ii)$ Positive and negative ions are formed by heterolytic cleavage of a covalent bond.
$(iii)$ Only homolytic cleavage is possible in the $C-Cl$ bond of $CH_3-Cl$.
$(iv)$ If heterolytic cleavage of a bond occurs,then ionic or polar type reactions take place.