Which of these can be classified as a pure substance?

Which reason best explains why metals are malleable? a)because they have delocalized electrons b)because they have localized electrons c)because they have ionic bonds d)because they have rigid bonds

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.

Which compound most likely has the greatest bond energy?