Question

Given the balanced equation representing a reaction:
Cl2(g) ==> Cl(g) + Cl(g)
What occurs during this change?
(1) Energy is absorbed and a bond is broken.
(2) Energy is absorbed and a bond is formed.
(3) Energy is released and a bond is broken.
(4) Energy is released and a bond is formed.

Answer 1

Energy is absorbed and a bond is Broken.
You Have the bond of Cl2 which has been broken into 2 Cl.
And in order to break, energy need to be absorbed. 

Hope this Helps :)

Answer 2

Answer is: (1) Energy is absorbed and a bond is broken.

This energy is called bond-dissociation energy.

Bond-dissociation energy is the measure of bond strength in a chemical bond.

Bond energy of chlorine molecule (sigma bond) is energy needed for breaking up one molecule of chlorine into two chlorine atoms.

When two chlorine atoms form molecule of chlorne, than energy is released and bond is formed.