From previous studies, I recalled in my lecture theatre today that lattice energy was the energy released when an ionic compounds is formed from individual atoms in the gaseous state. I thought this idea would follow through throughout my studies at university.
However, my lecturer this afternoon defined lattice energy as the following:
• For an ionic solid the lattice energy is defined as the energy required to completely separate a mole of solid ionic compound into its gaseous ions
I thought this was my definition but in the reverse order.
Which one of us is correct, the lecturer or myself?