Considering how the chapter ends with Jem wanting to keep Atticus's secret safe and then proclaiming he is just

like Atticus, a gentleman, what does that imply about Jem from what we have seen when his emotions were

involved? (chapter 10)

Answer: Jem's reaction illustrates his maturity, and implies that Jem has realized that his father is a brave and humble man.

Explanation:

In Chapter 10, Jem argues that Atticus is, unlike the rest of the parents, too old and boring. However, later on, when a mad dog is found down the street, Atticus shoots him. Scout, surprised by this event, does not understand why their father has kept his talent a secret.

Jem, on the other hand, is mature enough to understand that Atticus keeps quiet about his skills because he does not want to stand out from the rest of the people. Atticus does not think that his skills are something he should be proud of, nor does he think that demonstrating one's shooting skills will make one seem brave in front of other people. This is why he never shoots, unless he really has to. Jem is aware now that his father is a humble, yet courageous man.