Enthalpy of formation (ΔHf) = Enthalpy change when mole of a substance is formed from its constituent elements in their states.
Enthalpy of combustion (ΔHc) = Enthalpy change when mole of a substance undergoes combustion in oxygen.
First Ionisation enthalpy (ΔHi) = The enthalpy change when one mole of gaseous atoms loses electron per atom to produce gaseous ions
First Electron affinity (ΔHea) = The enthalpy change when of gaseous atoms gains one electron per atom to produce gaseous 1- ions.
Enthalpy of atomisation (ΔHa) = Enthalpy change when one mole of gaseous atoms is produced from an element in its normal state.
Hydration enthalpy (ΔHhyd) = Enthalpy change when of gaseous ions become hydrated (dissolved in water).
Enthalpy of solution (ΔHsol) = Enthalpy change when one mole of an ionic solid dissolves in an amount of water large enough so that the dissolved ions are well separated and do not interact with each other.
Bond dissociation enthalpy (ΔHdis) = Enthalpy change when one mole of covalent bonds is broken in the state.
Lattice enthalpy of formation (ΔHL) = Enthalpy change when one mole of a solid ionic compound is formed from its constituent ions in the phase.