Group 2

radii

increase, extra shell

outer electron more shielded

reactivity and 1st IE

reactivity increase, atoms more shielded

IE decrease, low EN

EN

decreases down the group because:

1. Larger atomic radius weakens the nucleus's pull on bonding electrons.

2. More electron shielding reduces the attraction between the nucleus and outer electrons.

3. Weaker effective nuclear charge results in less attraction for bonding electrons.

solubilities of OH

increase, decrease of lattice energy

solubility of SO4

decrease, increased lattice energy

lattice energy

energy required to break apart an ionic solid and convert its component atoms into gaseous ions

reaction with oxygen

Mg - white flame

Ca - white/red

Sr - red

Ba - pale green

all give white powder, metal oxide

reaction with water

Be doesn’t react - oxide layer

Mg - slow with water Mg(OH)2, vigorous with steam MgO

Ca, St and Ba give OH + H2

reaction with dilute acid

produce hydrogen gas and the corresponding metal salt

he reactivity of Group 2 metals with dilute acids generally increases down the group, with beryllium being the least reactive and barium being the most reactive.

Metal+2Acid→Metal Salt+H2

oxide + water

gives metal hydroxides

oxides + dilute acid

form the corresponding metal salts and water

All Group 2 oxides react with dilute acids, with the resulting salts being soluble in water.

Metal Oxide+2Acid→Metal Salt+H2​O

hydroxides + water

Do not react with water; instead, they either dissolve to form an alkaline solution or remain largely undissolved.

• Not very soluble, but solublility increases down the group

  • Larger metal ion, charge density decreases

  • Lower attraction between ions

  • Ions split away more easily

    • Greater concentration of OH^– ions in the water

hydroxides with dilute acids

form the corresponding metal salts and water

All Group 2 oxides react with dilute acids, with the resulting salts being soluble in water.

Metal Oxide+2Acid→Metal Salt+H2​O

carbonates + water

insoluble

carbonates + dilute acid

Metal Carbonate+2Acid→Metal Salt+CO2​↑+H2​O

carbon dioxide gas can be observed as effervescence

thermal decomposition of carbonates

The thermal stability of the carbonates generally increases down the group

Metal Carbonate→Metal Oxide+CO2

thermal decomposition of nitrates

Metal Nitrate→Metal Oxide+Nitrogen Dioxide+Oxygen

decomposition of nitrates often produces brown nitrogen dioxide gas

thermal stability of the nitrates increases down the group

uses

mg = fireworks and MgOH indegestion meds

Ca= limestone treat soil