Group 2 Elements

Flashcards covering various aspects of Group 2 elements' properties and reactions.

Group 2 elements

The alkaline earth metals, belonging to the s-block. Their oxides and hydroxides are alkaline.

Atomic (metallic) radii of Group 2 elements

They increase down the group because each element has an extra filled main level of electrons.

Melting points of Group 2 elements

They decrease slightly down the group (starting with calcium) as metallic bond strength decreases.

Reason for decreasing melting points in Group 2

The electrons in the 'sea' of delocalized electrons are further away from the positive nuclei.

Ionization energies of Group 2 elements

Both the first and second decrease down the group as electrons are further from the nucleus and are more shielded.

Reactivity of Group 2 metals

The metals become more reactive going down the group.

Lime kiln process

Calcium carbonate (limestone) is heated to produce calcium oxide (quicklime) and carbon dioxide.

Uses of quicklime (calcium oxide)

Used to make building mortar, treat acidic soils, and in making glass.

Oxidation of Group 2 metals in reactions

The metals are oxidized from oxidation state 0 to +2.

Reaction of magnesium with water

Magnesium reacts slowly with cold water but rapidly with steam.

Reaction of calcium with water

Calcium reacts more vigorously with cold water than magnesium.

Solubilities of Group 2 hydroxides

They increase down the group.

Solubility of magnesium hydroxide

It is almost insoluble and sold as a suspension in water (milk of magnesia).

Solubility of calcium hydroxide

Sparingly soluble and used as limewater.

Solubilities of Group 2 sulfates

They decrease down the group.

Solubility of barium sulfate

Virtually insoluble, allowing it to be used as a barium meal for medical X-rays.

Use of barium chloride in sulfate ion testing

Identifies the presence of sulfate ions by forming a white precipitate of barium sulfate.