I think c may be your anwser but im not too sure :/ srry if u get it wrong!
Moles = mass / molar mass
molar mass of O2 is 32
therefore moles = 72/32
= 2.25 moles
<span>The correct answer would be: 4 oxygen atoms</span>
The total energy can be found by adding the different energies:
628 + 15,600 + 712
= 16.94 kJ
