4Ionisation EnergyHard1 mark
Element X has a higher first ionisation energy than element Y.
Two students state one factor that helps to explain this.
student 1 'X has a higher first ionisation energy than Y because an atom
of X has more protons in its nucleus than an atom of Y.'
student 2 'X has a higher first ionisation energy than Y because X has a
smaller atomic radius than Y.'
Only one of the two students is correct.
Which elements could X and Y be?
| X | Y | |
|---|---|---|
| A | carbon | boron |
| B | magnesium | aluminium |
| C | oxygen | nitrogen |
| D | oxygen | sulfur |