Group 2

Group 2 Elements

Group 2 elements, also known as alkaline earth metals, include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

Basic Properties

  • Group 2 elements are s-block elements because their outermost electrons are in the s-orbital.
  • They have two electrons in their outermost shell, leading to their tendency to lose two electrons in reactions to achieve a stable electron configuration.
  • Group 2 elements are all metallic and shiny. They are generally harder than Group 1 metals, but still softer than transition metals.
  • They have low electronegativity and low electron affinity values.
  • Reactivity increases down the group; this is due to the increasing atomic sizes, and thus a lesser attraction between the outermost electrons and the nucleus.
  • They can react with halogens to form alkaline earth metal halides, and with hydrogen to form alkaline earth metal hydrides.
  • Magnesium, calcium, strontium and barium react with water to form hydroxides and release hydrogen. These reactions become more vigorous as you move down the group.

Oxidation States and Ionisation Energies

  • Group 2 elements typically show an oxidation state of +2 in their compounds.
  • The first and second ionisation energies of Group 2 elements are higher than those for Group 1 elements. This makes Group 2 elements less reactive than Group 1 elements.
  • Ionisation energies generally decrease down Group 2, because the outermost electrons are further from the nucleus and the increased number of electron shells shields the outermost electrons from the positively charged nucleus to a greater extent.

Uses of Group 2 Elements

  • Magnesium and its alloys are used in aircraft construction due to their high strength-to-weight ratio.
  • Calcium is a component of teeth, bones and shells.
  • Barium is used in the manufacture of paints and glass, and barium sulphate is used in medical imaging procedures.

Reflecting on these properties, it’s clear that Group 2 elements have a lot of distinct qualities that distinguish them from other groups in the periodic table.