The reactivity of redox reactions increases down group 2. The atoms have to lose two electrons to form +2 ions. The first and second ionisation energies decrease down the group because the attraction between the nucleus and outer electrons decrease as a result of increasing atomic radius and increasing shielding. The group 2 elements become more reactive and become stronger reducing agents down the group.first IE: M(g) → M+(g) + e-second IE: M+(g) → M2+(g) + e-
Ionisation Energies
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Specification: AQA Chemistry (7404), AS-level, 3.2.2 Group 2, the alkaline earth metals. Topic: Group 2.
Key terms in this lesson
- Shielding
- The repulsion of outer electrons by electrons in inner shells, which reduces the net attraction of the nucleus for the outer electrons.
- Reducing agent
- A species that donates electrons to another species, causing that species to be reduced.
- Atomic radius
- A measure of the size of an atom, found by measuring the distance between two adjacent nuclei and dividing by two.
- Group
- A vertical column of the periodic table, containing elements with the same number of outer-shell electrons.
More in Group 2
- Group 2 Elements
- Physical Properties
- Calcium
- Reaction with Water
- Solubility of Hydroxides
- Solubility of Sulfates
All 7 lessons in Group 2 · All AQA AS-level Chemistry topics