2.39. Dalton’s Atomic Theory http://www.ck12.org
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Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/54887The Billiard Ball Model
Because Dalton thought atoms were the smallest particles of matter, he envisioned them as solid, hard spheres, like
billiard (pool) balls, so he used wooden balls to model them. Three of his model atoms are pictured in theFigure
2.72. Do you see the holes in the balls? Dalton added these so the model atoms could be joined together with hooks
and used to model compounds.
FIGURE 2.72
Q:When scientists discovered smaller particles inside the atom, they realized that Dalton’s atomic models were too
simple. How do modern atomic models differ from Dalton’s models?
A:Modern atomic models, like the one pictured at the top of this article, usually represent subatomic particles,
including electrons, protons, and neutrons. For a fuller comparison of Dalton’s ideas and modern ideas, go to this
URL: