https://www.reddit.com/r/igcse/comments/134e725/most_common_chemistry_question_list_from_2015_to/
SUPER IMPORTANT LIFESAVER DOCUMENT ^^
https://www.reddit.com/r/igcse/comments/13dg5m6/most_common_chemistry_atp_question_list_from_2015/
States Of Matter
Separation & Purification
Atoms And Elements
Atoms Combining
Moles
Redox Reaction
Electricity & Chemical Change
Rate Of Reaction
Periodic Table
The Behaviour Of Metals
Making Use Of Metals
Energy Changes
Processes
Equilibrium And Reversible Reactions
Environmental Chemistry
Acids, Bases & Salts