The element which readily forms an ionic bond has the electronic configuration.
1s22s22p3
1s22s22p63s1
1s22s22p1
1s22s22p2
Metals form ionic bond as they have low ionization energies.
1s2 2s2 2p6 3s1 : Sodium metal
Element X has an electronic configuration of (2,8,2) and Element Y has an electronic configuration of (2,6).The compound formed by X and Y is covalent.