Test your knowledge with free interactive questions on Seneca — used by over 10 million students.

Properties of Group 2 Metals

Elements in the same group have similar properties. Here, we shall look at the similarities between the properties of the Group 2 elements.

Atomic radius and ionisation energy

Atomic radius and ionisation energy

  • Atomic radius increases as you go down Group 2.
    • This is because each extra electron shell is further away.
  • Ionisation energy decreases as you go down Group 2.
    • This is because the outer electrons are further away and experience less attraction to the nucleus.
Melting point

Melting point

  • Melting points decrease as you go down Group 2.
    • This is because the ion cores have larger radii down the group.
    • The free electrons experience less attraction to the nuclei because of the larger radii.
    • The bonding is weaker, so the melting point is lower.
  • Magnesium has an anomalously low melting point.
    • This is because it has a different crystal structure to the rest of Group 2.
Reactions with water

Reactions with water

  • Group 2 metals react with water to form metal hydroxides. For example:
    • Mg + 2H2O → Mg(OH)2 + H2
  • Reactivity increases as you go down Group 2. This is because the lower elements have lower ionisation energies.
    • Beryllium is an exception. If beryllium were to lose two electrons it would be tiny and have a very high charge density. This would make it unstable and so beryllium doesn't react with water.
Solubility of salts

Solubility of salts

  • The solubility of hydroxides increases as you go down Group 2.
    • Magnesium hydroxide is very insoluble. The phrase to use for this is 'sparingly soluble'.
  • The solubility of sulfates decreases as you go down Group 2.
    • Barium sulfate is completely insoluble.

Uses of Group 2 Compounds

Group 2 compounds have a number of uses in industry and society. Examples of these uses include:

Titanium extraction

Titanium extraction

  • The first step in the extraction process is converting titanium ore (TiO2) to titanium chloride (TiCl4) using chlorine gas and carbon.
  • The second step involves heating TiCl4 with magnesium metal at 1,000oC. The equation for this step is:
    • TiCl4(g) + 2Mg(l) \rightarrow Ti(s) + 2MgCl2(l)
As bases to neutralise acids

As bases to neutralise acids

  • Calcium hydroxide (sometimes called slaked lime) and magnesium hydroxide are used to neutralise acids.
    • Calcium hydroxide is used to neutralise acidic soils in agriculture.
    • Magnesium hydroxide is used in indigestion tablets as an antacid that neutralises excess stomach acid.
In healthcare

In healthcare

  • 'Barium meals' (made of barium sulfate) are used in healthcare.
  • X-rays can detect solid materials like bones but aren't very good at detecting soft tissues.
  • 'Barium meals' are insoluble and reflect X-rays.
    • A barium meal coats the oesophagus, stomach, and intestines and makes the structure of them show up on X-rays.
Wet scrubbing

Wet scrubbing

  • Wet scrubbing is the process of removing SO2 from flue gases.
    • Flue gases come from chimneys and industrial waste.
  • CaO and CaCO3 are used to remove the SO2 from the gases.
    • This works because SO2 is acidic and the calcium compounds are bases.
  • The CaO is mixed with water and sprayed onto the gases.
    • The byproduct is calcium sulfite, CaSO3.
Jump to other topics
1

Physical Chemistry

1.1

Atoms, Molecules & Stoichiometry

1.2

Atomic Structure

1.3

Chemical Bonding

1.4

States of Matter

1.5

Chemical Energetics

1.6

Electrochemistry

1.7

Equilibria

1.8

Partition Coefficient

1.9

Reaction Kinetics

2

Inorganic Chemistry

3

Organic Chemistry & Analysis

3.1

Introduction to Organic Chemistry

3.2

Hydrocarbons

3.3

Halogen Derivatives

3.4

Hydroxy Compounds

3.5

Carbonyl Compounds

3.6

Carboxylic Acids & Derivatives

3.7

Nitrogen Compounds

3.8

Polymerisation

3.9

Analytical Techniques

3.10

Organic Synthesis

Practice questions on Group 2 Chemistry

Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
Answer all questions on Group 2 Chemistry

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium