Presentation on theme: "Elements & Atoms Atomic theory grew as a series of models that developed from experimental evidence. As more evidence was collected, the theory and models."— Presentation transcript:
1 Elements & AtomsAtomic theory grew as a series of models that developed from experimental evidence. As more evidence was collected, the theory and models were revised.
2 Elements & AtomsDalton Model – atoms are like smooth, hard balls that could not be broken into smaller pieces. (See p. 8 – Summary of Dalton’s Ideas)Solid Sphere Model or Billiard Ball Model proposed by John Dalton
3 Elements & AtomsThomson Model – atoms have negatively charged electrons embedded in a positive charge.Plum Pudding Model or Raisin Bun Model proposed by J.J. Thomson
4 Elements & AtomsRutherford’s Gold Foil Experiment – most particles pass through foil in straight line, but a few were strongly deflected. This led to proposal of Rutherford Model, small, positively charged nucleus in center of the atom.Rutherford Model of a lithium atom.
5 Elements & AtomsBohr’s Model – electrons move in specific orbits around the nucleus of an atom.The Bohr atom
6 Elements & AtomsCloud Model – electrons move rapidly in every direction around the nucleus.
7 Elements & AtomsModern Atomic Model – nucleus, which contains both protons and neutrons, is surrounded by a cloudlike region of electrons.