For the second period elements the correct increasing order of first ionisation enthalpy is:
Li < B < Be < C < O < N < F < Ne
Li < B < Be < C < N < O < F < Ne
Li < Be < B < C < O < N < F < Ne
Li < Be < B < C < N < O < F < Ne
Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor. M is :
Mg
Ca
Sr
Be