Atoms in all compounds are held by forces called chemical bonds. Chemical bonds are the attractive forces that hold atoms together to form molecules or compounds. There are three main types of chemical bonds: covalent bonds, ionic bonds, and metallic bonds.

* Covalent bonds form when two or more atoms share electrons. This type of bond is the strongest and most common type of chemical bond.

* Ionic bonds form when one or more atoms transfer electrons to another atom. This type of bond is less strong than a covalent bond, but it is still relatively strong.

* Metallic bonds form when the outermost electrons of the atoms in a metal are delocalized, meaning that they are not associated with any one particular atom. This type of bond is the weakest type of chemical bond.