Group 7

• Group Seven Elements


  Molecules with two atoms
• Moving down Group Seven

  Melting and boiling points of the group seven elements increase
• Group Seven is also called the halogens
• All the elements in Group Seven are non-metals
• Group Seven elements


  Have seven electrons in their outer energy level
• Formation of Group Seven molecules

  1. Two atoms of a Group Seven element overlap their outer energy levels

  2. They share a pair of electrons

  3. This shared pair of electrons is called a covalent bond

  4. Every Group Seven element forms a molecule consisting of two atoms joined by a covalent bond
• We can represent the covalent bond as a stick between the two atoms
• Physical states of Group Seven elements at room temperature

  • Fluorine - gas
  • Chlorine - gas
  • Bromine - liquid
  • Iodine - solid
• Moving down Group Seven

  Relative molecular mass of the halogens increases
• Relative molecular mass gives an idea of the size of a molecule</b>