Group 2

• What is the chemical symbol for beryllium?

  Be
• The electron configuration of magnesium is 1s² 2s² 2p⁶ 3s²
• Group 2 elements have high melting points due to their strong metallic lattice structure
• Why are Group 2 elements harder and denser than Group 1 elements?

  Smaller ion size
• The atomic radius of Group 2 elements increases as you move down the group.
• The first ionization energy of Group 2 elements decreases down the group.
• What happens to the melting points of Group 2 elements as you move down the group?

  Decrease
• The reactivity of Group 2 elements with water increases as you move down the group.
• Order the observations of magnesium reacting with cold water

  1️⃣ Very slow reaction

  2️⃣ Few bubbles on the surface

  3️⃣ White solid produced
• Magnesium reacts with steam to produce a white light and magnesium oxide.
• What is observed when calcium reacts with cold water?

  Effervescence
• The equation for the reaction of calcium with water is Ca (s) + 2H₂O (l) → Ca(OH)₂ (aq) + H₂
• What is the general trend in reactivity of Group 2 elements with water?

  Increases down the group
• Match the change in oxidation state with the process:

  +1 to 0 ↔️ Reduction

  0 to +2 ↔️ Oxidation
• Magnesium is used in the extraction of titanium from TiCl₄ due to its ability to reduce the compound.
• What is the balanced equation for the reaction between TiCl₄ and magnesium?

  TiCl₄ + 2Mg → Ti + 2MgCl₂
• The solubility of Group 2 hydroxides in water increases as you move down the group.
• Magnesium hydroxide is used in medicine as an antacid to neutralize excess stomach acid.
• What happens to the solubility of Group 2 sulfates as you move down the group?

  Decreases
• Match the Group 2 ion with the expected precipitate when reacting with sodium hydroxide:

  Mg²⁺ ↔️ Thick white precipitate

  Ba²⁺ ↔️ Colourless solution
• Barium salts are used to test for the presence of sulfate ions.
• Why is barium sulfate used in medicine as a contrast agent for X-rays?

  Absorbs X-rays
• Barium ions are toxic, but barium sulfate is harmless because it is insoluble.
• What are magnesium salts used to test for?

  Hydroxide ions
• Calcium oxide reacts with sulfur dioxide to form calcium sulfite.
• The trends in atomic radius and first ionization energy of Group 2 elements can be explained by changes in shielding and nuclear attraction.