Answer:
a )Li
b)O
c)F
Explanation:
a) Li-1s^2 2s^1
F-1s^2 2s^2 2p^5
it is easy to pull out e- from 2p orbit than 2s because 2s orbit is close to nucleus.Therefore Li have high ionisation enthalpy
b)oxygen ion is larger than Na because o have fewer proton
c)F because it requires only 1e to achieve stable noble gas configuration.Therefore to achieve stable nobke gas electonic configuration it accept 1e.
