Element X has a greater first ionisation energy than element Y. Two students each give what they think is a reason for this. student 1: "X has a greater first ionisation energy than Y because an atom of X contains more protons in its nucleus than an atom of Y." student 2: "X has a greater first ionisation energy than Y because X has a smaller atomic radius than Y." Only one of these students is right. What could X and Y be?
- AX: carbon; Y: boron
- BX: magnesium; Y: aluminium
- CX: oxygen; Y: nitrogen
- DX: oxygen; Y: sulfur