# Why oxidation state decreases

oxides of group 1 elements are Li2O , Na2O2 , KO2 , RbO2 Oxygen’s oxidation state in each compound is -2 , -1 , -1/2 ,-1/2 respectively I.e oxide-> peroxide-> superoxide

my question The oxidation state of the oxygen Is increasing down the group why is that ?

My attempt

the tendency to donate electron increases down the group , by this statement the oxidation state of oxygen in the oxides down the group should decrease as oxygen gets easily reduced.

What am I missing here?

• What about the size of the cations? – Karsten Theis Apr 3 at 12:58