Which has more energy, a chlorine atom or a chlorine molecule?

1 Answer
Jan 13, 2017

The chlorine atom has more energy.


Bond breaking is an endothermic (energy absorbing) process.

Consider the breaking of a #"Cl-Cl"# bond:

#"Cl-Cl" → "Cl· + ·Cl", ΔH = "+243 kJ/mol"#

Since 243 kJ/mol have been added to the system to form the atoms, the chlorine atoms must have a higher energy than the chlorine molecules.