[plt-scheme] Help with symbols

Hi,

I have a question about symbols in Scheme.

(symbol? '5) => #f

Is this the case because 5 is self-evaluating and for lack of a better
term, "5 is 5"?

(symbol? '(+ 1 2)) =? #f

Is this the case because it is a quoted list, and not a "name"?

I see that I don't know much more about symbols other than they are a
quoted sequence of characters about which I am not sure of the
restrictions. Is there more to know about them? Where?

Best wishes,

Grant