The atomic radius increases down the group as each atom has an extra filled main level compared with the one above.Reactivity decreases down the group because although the nuclear charge increases, the distance between the nucleus and bonding pair of electrons increases.
Size of Atoms
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Specification: AQA Chemistry (7404), AS-level, 3.2.3.1 Trends in properties. Topic: Group 7.
Key terms in this lesson
- 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 7
- Halogens
- Physical Properties
- Electronegativity
- Melting and Boiling Points
- Trends in Oxidising Ability
- Displacement Reactions
- Halide Ions as Reducing Agents
- Sodium Chloride with Sulfuric Acid
All 20 lessons in Group 7 · All AQA AS-level Chemistry topics