Full Idea
In general, nuclear charge is the overwhelming determinant of an element's chemical behaviour, while nuclear mass is a negligible factor.
Gist of Idea
Generally it is nuclear charge (not nuclear mass) which determines behaviour
Source
Robin F. Hendry (Chemistry [2008], 'Micro')
Book Reference
'Routledge Companion to Philosophy of Science', ed/tr. Psillos,S/Curd,M [Routledge 2010], p.522
A Reaction
The exception is the isotopes of very light elements light hydrogen.
Related Ideas
Idea 17477 Defining elements by atomic number allowed atoms of an element to have different masses [Hendry]
Idea 17481 Nuclear charge (plus laws) explains electron structure and spectrum, but not vice versa [Hendry]