Group 7 elements (the halogens) become less reactive down the group.
Which statement explains why?
The outer shell is closer to the nucleus, so an incoming electron is attracted more strongly.
The outer shell is further from the nucleus, so an incoming electron is attracted less strongly and gained less easily.
There is less shielding from inner electron shells, making it harder to gain an electron.
The nuclear charge decreases down the group, so it cannot attract an extra electron.
41 exam-style questions on OCR GCSE Chemistry Predicting chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.