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Reactivity

Key Stage 4

Meaning

Reactivity is how vigorously a chemical will react.

About Reactivity

Reactivity is determined by how easily an element can lose or gain electrons.
Electrons are held in orbit around the nucleus because the electrons are negatively charged and are attracted to the nucleus which is positively charged.
If an element loses electrons easily it is highly reactive.
If an element gains electrons readily it is also highly reactive.

Three important factors affect reactivity of elements.

Reactivity in Groups 1, 2 and 3

Group1ElectronShells.png
Group1ElectronShielding.png
In a chemical reaction the electron in the outer shell is lost.

The reactivity increases as you go down the group because:

Reactivity in Group 7

Group7ElectronShells.png
Group7ElectronShielding.png
In a chemical reaction an extra electron is added to the outer shell.

The reactivity decreases as you go down the group because:

Reactivity along Period 2

Period2ElectronShells.png
Period2ElectronShielding.png
For the first 3 elements Lithium, Beryllium and Boron all lose electrons in chemical reactions.

The reactivity decreases as you go across the period because:

Nitrogen, Oxygen and Fluorine can all gain electrons to become negative ions in certain reactions.

The reactivity increases as you go across the period because:


References

AQA

Reactivity; alkali metals, pages 26-27, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Reactivity; metals, pages 26-27, 84-89, 220-221, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Reactivity; periodicity, pages 19, 30-31, GCSE Chemistry; Third Edition, Oxford University Press, AQA

Edexcel

Reactivity, pages 86-87, GCSE Chemistry, Pearson, Edexcel

OCR

Reactivity; metals, pages 70-71, 125, 133, 141-143, Gateway GCSE Chemistry, Oxford, OCR
Reactivity; noble gases, page 137, Gateway GCSE Chemistry, Oxford, OCR
Reactivity; practical activities, pages 264-265, Gateway GCSE Chemistry, Oxford, OCR
Reactivity; trends in Periodic Table, pages 133, 135, 137, 142-143, Gateway GCSE Chemistry, Oxford, OCR