2.2 Group 2

First Ionisation energy increases across group 3 because of increased nuclear charge, decreased atomic radius and same electron shielding means more energy is needs to remove the first electron. Dips at Al because: outer electron is in a 3p orbital, higher energy than 3s orbital → less energy needed to remove electron Dips at S because one 3p orbital contains two electrons → repulsion between paired electrons → less energy needed to remove one

Decreases because: number of filled electron shells increases down the group → increased shielding, increased atomic radius → weaker force between outer electron and nucleus → less energy needed to remove electron

Increases (Mg least → Ba most) Because outer electrons further from nucleus and more electron shielding, so electrons are lost more easily

Increases down the group Mg(OH)₂ is almost insoluble Ba(OH)₂ creates a strong alkaline solution

Decreases down group MgSO₄ is soluble BaSO₄ is insoluble

Decreases down group because sea of delocalised electrons is further from the positive charge of the nucleus → weaker metallic bonds / forces of attraction which take less energy to weaken

Increases as there are more occupied electron shells down the group

Gases produced by power stations which are harmful to the environment

Used to neutralise soil

Milk of magnesia - antacid to treat indigestion, heartburn, wind etc.

In barium meals to outline gut in X-rays Ba²+ is toxic but is fine as barium sulphate is insoluble

Add to sample with HCl, white ppt will form if sulfate ions present