Pair reversal

Definition

A pair of elements whose order does not follow increasing relative atomic mass because the chemically appropriate order is the reverse.

Used by Edexcel

Specification 1.15 · Paper 1, Paper 2

1
When explaining a pair reversal, link the ideas explicitly: relative atomic mass is a weighted mean affected by isotope abundance, so strict mass order can conflict with the order supported by chemical properties.

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GCSE Chemistry · key term

A pair of elements whose order does not follow increasing relative atomic mass because the chemically appropriate order is the reverse.

Used by Edexcel

Specification 1.15 · Paper 1, Paper 2

1
When explaining a pair reversal, link the ideas explicitly: relative atomic mass is a weighted mean affected by isotope abundance, so strict mass order can conflict with the order supported by chemical properties.

Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.