Covalent compounds happen when the electrons are shared by the atoms and ionic compounds happen when electrons are donated from one atom to another. We talked about compounds and molecules in the matter section. When we discuss changes to matter, the changes are because of physical forces. When we talk about compounds, bonds are formed and broken down by chemical forces. Compounds cannot be broken down by physical forces.
Chemical forces are forces caused by other compounds, or molecules.
There are millions of compounds everywhere. Chances are, everything you can see is one type of compound or another. When elements join together and become compounds they lose their individual traits. Sodium alone is very reactive. The compound has none of the traits or the original elements.