- Group 7: Halogens -

• Group 7 contains non-metal elements
• Group 7 is placed in a vertical column on the right of the periodic table
• The elements in group 7 are called the halogens
• When an element in group 7 takes part in a reaction, its atom's outer shells gain an electron and form negatively charged ions, called anions
• The less easily these anions form, the less reactive the halogen
• Going down group 7:

  • The atoms become larger
  • The outer shell becomes further from the nucleus
  • The force of attraction between the nucleus and the outer shell decreases
  • An outer electron is gained less easily
  • The halogen becomes less reactive