2. 400 BC Democrituswas the firstscientist to suggest that all matter iscomposed of tiny, individual particlescalled atoms. (Atomos)
3. Elements are made up of atoms.Atoms are thesmallestparticle intowhich an element can be divided andstill retain its identity.An element is matter madeup of onlyONEtype ofatom.
4. TheAtomic Theorywas proposedbyJohn Daltonin the late 1700’s.This theory was based on theexperimentation and data of otherscientists.
5. Atomic Theory1.All matter is made of atoms2.Atoms cannot be divided3.Atoms of a particular element areexactly alike4.Atoms can join with other atoms tocreate new substances .
5. Since then, other scientist haveexpanded on our understanding of atomsin the following ways.-1897JJ Thompsonused the cathode raytube to find negative particles within theatom , which he namedelectrons. (Hecalled his model the Plum pudding model)