How are the terms "ionization energy"
and "electron affinity" related to each
other?

Ionization energy is the energy required to remove an electron away from an atom, which can be written as IE. ... Electron affinity, on the other hand, is the energy released when an electron is added to the atom. On the periodic table, electron affinity usually decreases down a group, and increases across a period.

Explanation:

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.