An answer key provides the correct final result (e.g., "The pH is 4.5"). A marking scheme details how to get there. It dictates:
Never leave a calculation blank. Even if you get stuck, invent a logical number and keep going. 3. Keywords and "M1, M2, M3" marking scheme chemistry
In many boards, forgetting (s) , (l) , (g) , or (aq) can cost you a mark in an equation. An answer key provides the correct final result (e