3.1.2 group 2

Increases down the group Atoms have more electron shells

Decreases down the group Metallic bonding weakens as atomic size increases Distance between positive ions and delocalised electrons increases So, electrostatic forces between positive ions and delocalised electrons weakens

enthalpy change when one mole of gaseous ions with a single positive charge forms one mole of gaseous ions with a double positive charge Ti+(g) > Ti+2(g) + e-

Increases down the group As atomic radius increases there is more shielding Nuclear attraction deceases and it is easier to remove outer electrons Cations form more easily

Burn in oxygen Mg burns with bright white flame - MgO is a white solid

Produces oxide and hydrogen

Hydroxide + hydrogen Makes water alkaline

Fizzing - more vigorous down group Metal dissolving - faster down group Solution heating up - more down group With calcium - white precipitate appearing

Form salt and hydrogen

Hydroxide formed of varying solubility

Milk of magnesia - used as medicine (Mg(OH)2) Calcium hydroxide - used in agriculture to neutralise acidic soils

calcium hydroxide (lime water) Limewater turns cloudy as white calcium carbonate is produced Ca(OH)2 + CO2 > CaCO3 + H2O