group 2

• what are the group 2 metals called?

  the alkaline earth metals
• which elements do we focus on?

  magnesium to barium
• how does atomic radius change down group 2?


  atomic radius INCREASES as you go down group 2
• how does ionisation energy change down group 2?

  first ionisation energy DECREASES as you go down group 2
• how can the increase in atomic radius be explained?

  • as we move down, each of the elements has an additional energy level of electrons added.
  • so an increase in the shielding effect and a decrease in the force of attraction between the protons in the nucleus and the outermost electrons.
  • so, the outermost electrons are held less tightly to the nucleus so they aren't held in shape as well so the atomic radius increases.
• how can the decrease in first ionisation energy be explained?

  • as we go down group 2, each of the elements has an additional energy level of electrons added.
  • so an increase in the shielding effect and a decrease in the force of attraction between the protons in the nucleus and the outermost electrons.
  • so, the outermost electrons are held less tightly to the nucleus and it takes less energy to remove them
  • so first ionisation energy decrease.