Argon is used to fill the gap between the glass panes in double-glazed window units.
State one property of argon, apart from it being chemically inert, that makes it suitable for this use.
[1]
Markscheme
7.3 Group 0 Questions
44 exam-style questions on Edexcel GCSE Chemistry 7.3 Group 0, covering 7.3.1 The noble gases. Each one has a worked solution and a mark scheme showing where the marks go.