Naughty America - Professor Mellanie Monroe helps student

Naughty America. Nobody, nobody, nobody does it better.

Now Lucas, listen to me. We've been doing this after school tutoring every other day for the past two months.

I know that you know this, you just need to find a way to be a little bit less nervous.

Well, how am I supposed to be less nervous when if I don't pass the exam tomorrow, I have to repeat this class next year?

So, can you tell me the name of the process that results in metal rusting?