The tiny core of an atom containing most of the mass of the atom and all of its positive charge is called the:

The answer is the nucleus. Hope this helped!

All of its positive charge is called the nucleus

Polymerization reaction

Remember that rust prevented by placing a sacrificial electrode in electrical contact with the iron. the sacrificial electrode must be composed of a metal that  oxidizes  more easily than iron (that is, it must be below iron in table 18.1).