Elements

• There are 92 naturally occurring elements
• Element


  A substance that's made of only one type of atom
• Examples of elements


  • Gold
  • Oxygen
• Elements can chemically combine to form compounds
• Compound


  A substance formed by the chemical combination of two or more elements
• Types of compounds


  • Covalent
  • Ionic
• Ion


  An atom or molecule that has gained or lost one or more electrons
• Metal ions are positive, non-metal ions are negative
• Balancing chemical equations


  Ensure the same number of atoms of each element on both sides of the equation