Elements X and Y belong to the same group in the Periodic Table. The table gives the first six ionisation energies of X and Y in $\text{kJ mol}^{-1}$. What might the identities of X and Y be?
- AX: antimony, Sb; Y: arsenic, As
- BX: arsenic, As; Y: antimony, Sb
- CX: selenium, Se; Y: tellurium, Te
- DX: tellurium, Te; Y: selenium, Se