One page editable worksheet can be used as a preview, review, assessment, etc. Define-Matter, Atom, Nucleus, Proton, Neutron, Electron, Spectral Line, Energy Level, Electron Cloud, Element, Atomic Number, Mass Number, Isotope, Average Atomic Mass, Ion.Understanding Concepts1) Illustrate an atom. Include protons, electrons, and neutrons. 2) Compare the mass, location, and charge of the three basic particles of an atom. 3) List Dalton’s three observations. 4) Illustrate Thomson’s, Rutherford’s, an