1. James Chadwick
Ariana, Colby, and Lindsey

2. Previous model - Rutherford

3. Chadwick’s Experiment
– Chadwick discovered an unknown particle in the
nucleus.
– Predicted by Ettore Majorana, who found it
because of its lack of electrical charge
– Chadwick used Rutherford’s zinc shield and
inferred neutrons do not need to overcome any
coulomb barrier and can therefore penetrate and
enter the nuclei of even the heaviest elements.

4. Rutherford’s
experiment

5. Chadwick’s Model
ft. Bill Nye the ‘Psy’ence guy

6. • Chadwick discovered neutrons in the nucleus,
which helped define atom’s mass.