The multiple oxidation states of transition metals are due to which of the following properties?

Which of the following is true about transition metals?

I. Transition metals form acidic oxides

II. A transition metal can have multiple oxidation states

III. Transition metals can be reduced, but can never be oxidized

What class of element is zinc?

There is a unknown element in a jar. It is a solid at room temperature and conducts electricity. Which of the following could be true about this element?

An unknown element has been studied in the lab. It has been shown to be malleable, ductile, and a good conductor of heat. Which element best fits this description?