Learning Intentions

• You can examine a timeline on the board for each scientist and their contribution to the atomic theory to visualize the order of events using a PowerPoint.

• You can match a description of a discovery that lead to our current atomic theory, with a picture of the experiment or device used to make the discovery, and then a picture and name of the scientist that made the discovery.

Content Standards being covered:

Student understands the structure of matter at the atomic level and the history that lead to our current understanding.
57.Democritus, an ancient Greek, was the first to conceptualize the atom and called this theoretical particle “atomos”, meaning indivisible
58. John Dalton proposed the “Atomic Theory”- 4 key ideas that impact our understanding of Chemistry to this day
59. Dmitri Mendeleev proposed a pattern for organizing elements in 1869 that has developed into the modern, most commonly used, Periodic Table
60. J.J. Thomson used cathode rays to discover the electron
63. R.A. Millikan used the oil drop experiment to discover the mass of an electron
64. Using the gold foil experiment, Ernest Rutherford discovered a very small and very dense positively charged nucleus at the center of an atom.
65. Neils Bohr proposed an atomic structure that described electrons orbiting the nucleus like planets around the Sun
66. James Chadwick discovered the neutron using alpha particles
67. Ernest Shrodinger used his equation to explain the wave nature of the electrons that led to the quantum mechanic model of the atom.

Habits of Mind/Life skills being covered:

Thinking Flexibly

Thinking Interdependently

Striving for Accuracy

Journal Entry:

What scientists can you remember from the presentations? (try not to use your notes) What did they contribute?