- A compound (chemical compound) is formed when different elements react with each other, forming bonds between their atoms.
- There are four types of compounds, depending on how the constituent atoms are held together:
- Molecules held together by covalent bonds
- Ionic compounds held together by ionic bonds
- Intermetallic compounds held together by metallic bonds
- Complexes held together by coordinate covalent bonds
- When a compound is exposed to a new element further reactions can take place which can produce new compounds.
- A molecule consisting of atoms of only one element is not a compound.
- A compound differs from a mixture because the atoms in a mixture are not bonded together.
- A mixture contains different elements but no chemical reaction takes place, so each element remains separate and distinct.