Does Facebook use normalize.css and jQuery?

Answer 1

The simple answer is no.

To find out about front-end technology used on a particular webpage, the source-code and your browser's dev-tools are your friend. Familiarize yourself with the network, console and inspector/elements tabs of your dev-tools. I cannot emphasize enough how much it will help you developing. A deeper dive into the debugging, auditing and monitoring capabilities as well as triggering states or resolution will be a game-changer for people having worked without it.

Being able to do so will quickly reveal what facebook does and doesn't use.