MATTER UNIT STRUCTURE OF AN ATOM. Atom : the smallest unit of matter that retains the identity of the substance.
Atomic Structure
Learning Goal #3: Discriminate between the relative size, charge, position, and number of protons, neutrons, and electrons of different elements.
AQA Chemistry Unit 1. Atoms All substances are made of atoms An element contains only one type of atom A compound contains more than one type of atom.
