What this tests
Syllabus point 10.3 — Air quality and climate, in Chemistry of the environment. Difficulty easy (estimated from the question's demands, not a Cambridge rating).
Also set in
The same question, as Cambridge printed it in other papers.
Cambridge IGCSE Chemistry 0620 · 10.3 Air quality and climate
November 2013 · Paper 11 · Question 33
One real Cambridge question from Chemistry of the environment, with the official answer. Cambridge has printed this question 2 times.