which elements are metals
Silver (Ag) and copper (Cu) are some of the most efficient metals and are often used in electronics. 2. Reactivity: Metals are very reactive, some more than others, but most form compounds with other elements quite easily. Sodium (Na) and potassium (K) are some of the most reactive metals. A metal like iron (Fe) forms iron oxide (Fe2O3), which you know as rust. 3. Chemical: It gets a little complex here.