Many of our kitchen appliances are made of Stainless Steel. Stainless steel is better than normal steel because stainless steel doesn't rust.

But, what is it about stainless steel that prevents rusting? In fact, when there are so many elements, why do some elements react with one another, and some don't?

To understand why, you need to first understand how electrons are distributed in an atom, and how they move from one atom to another. That's exactly what we will do in this module!