Full Idea
Planck's quantum idea explained so much, including the observation that the chemical world is made up of discrete units - the elements. Discrete elements implied fundamental units of matter that were themselves discrete (as Dalton had said).
Gist of Idea
Quantum theory explains why nature is made up of units, such as elements
Source
Peter Watson (Convergence [2016], 4 'Intro')
A Reaction
The atomic theory was only finally confirmed by Einstein in 1905. This idea implies that the very lowest level of all must have distinct building blocks, but so far we have got down to 'fields', which seem to be a sort of 'foam'.
Book Reference
Watson,Peter: 'Convergence' [Simon and Schuster 2016], p.107