Final answer:
Jem reacts with anger to Scout's question about Mrs. Gates's prejudice, instructing her not to discuss it, likely due to the traumatic impact of Tom Robinson's trial and the revealed hypocrisy in his community.
Step-by-step explanation:
When Scout asks Jem about Mrs. Gates's prejudice toward Tom Robinson, Jem reacts strongly and with anger, which is a stark contrast to her confusion. He sharply tells Scout not to talk about it, which signals that he is deeply disturbed by the hypocrisy and injustice he has witnessed during the trial.
Jem's reaction is likely due to his traumatic experience with the Tom Robinson case, which has been a jarring coming-of-age moment for him. He saw firsthand the destructive nature of racism and the failure of the justice system, and this has shattered his previous belief in fairness and the goodness of the community in which he lives.
In the novel To Kill a Mockingbird, Jem reacts to Scout's question about Mrs. Gates's prejudice toward Tom Robinson by getting angry and upset. He feels betrayed and confused because he thought Mrs. Gates was a good person who stood up against injustice.
This reaction is most likely because Jem is beginning to understand the hypocrisy and prejudice in the world, and he is disappointed to discover that even someone he respected can be biased.