chemistry

• A symbol is a short way of representing an element.
• A formulae is used to represent molecules , compounds and radicals.
• The valency of an element is its combining power.
• A diatomic is 2 atoms chemically combined together
• Three diatomic elements are:

  1. Hydrogen
  2. Nitrogen
  3. Oxygen
• A radical is a group of atoms chemically combined together and behaves as a single unit.