Question 21
Question 21 of 40
Question image for Q21
Periodic Table
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No letter options?
Older MCQs might not have the typical A, B, C, D choices. They have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such combinations to the answer.
A 1, 2 and 3 are correct
B 1 and 2 only are correct
C 2 and 3 only are correct
D 1 only is correct
Topics Tested
6. Chemical reactions
6.2. Rate of reaction

State that a catalyst increases the rate of a reaction, decreases the activation energy, E_a, of a reaction and is unchanged at the end of a reaction

5. Chemical energetics
5.1. Exothermic and endothermic rea...

Define activation energy, E_a, as the minimum energy that colliding particles must have to react