A compound is a substance made from the combination of two or more elements and held together by chemical bonds that are difficult to break. The bonds form as a result of sharing or exchanging electrons among atoms. The smallest unbreakable unit of a compound is a molecule.

  • 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.