If its the title, 'on' can be capitalized to put emphasis. Else, there no such rule to capitalize it.
Yes, chapters are typically capitalized in a book.
Yes, "Book Fair" should be capitalized as it is a proper noun.
The word evolution does not need to be capitalized.
No, coral does not need to be capitalized.
Yes, the chapter on climate change in the book is properly capitalized.
yes, it should be capitalized
No.
No, circa does not need to be capitalized.
No, it doesn't need to be capitalized.
No, it shouldn't be capitalized.
Yes, "Penguin" should be capitalized when referring to the animal or the book publishing company.
Yes, book names are typically capitalized. The first word, last word, and all other important words in the title should be capitalized. However, conjunctions, articles, and prepositions are usually not capitalized unless they are the first word of the title.