what is the formula of oxide of element M having ionisation energies as –

IE1 = 100, IE2 = 250 , IE3= 250 , IE4 =1500 kJ .

OPTIONS: M2O3, M2O , MO2 MO…...

what is the exact formula??

see the oxidation state of the oxygen atom is 2-.therefore the formula will be M2OX
where x represents the oxidation state of element M
for finding the oxidation state of the element M is
here the ionisation energy is increasing not rapidly,it means that it is easy to remove the electron from its outermost orbit.
but the fourth IE is 6 times higher.It means that the 4^th electron cannot be removed easily.So in +3 oxidation state it is gaining stability.
So the formula will be M2O3