Easy
Which of the following best explains why a freshly cut apple turns brown after being left in air for some time?
Explanation
Explanation
The browning of a cut apple (or potato) is due to oxidation: enzymes in the fruit catalyse a reaction between certain compounds and atmospheric oxygen, producing brown-coloured substances on the exposed surface.
PRO TIP
Re-check your working by substituting the answer back into the original question.