Discovery of the
Nucleus
Protons and Neutrons
Who were they?
Ernest Rutherford is a physicist who won the Nobel Prize for chemistry. He
discovered the concept of radioactive half-life and theorized that atoms have their
charge concentrated in a very small nucleus.
Hans Geiger is a German physicist. He is a co-inventor of the Geiger counter. He is
also well known for the discovering the atomic nucleus.
Ernest Marsden is an undergraduate he performed the Geiger-Marsden
Experiment. After serving in WWII as a Royal Engineer, he became the leading
scientist in New Zealand. He founded the department of scientific and industrial
research.
James Chadwick is an English physicist who was awarded the Nobel Prize for
discovering the neutron. He was also the head of the British scientists who
worked in Manhattan.
Theories & Models
Rutherford’s model of the atom was simplified in a well known symbol
showing electrons circling around the nucleus, similar to the planets
orbiting the Sun.
Radioactivity is shown to be accomplished in which new types of matter
are being continually produced.
Chadwick Theory & Model
Predicted that the atom would have a neutron. He then discovered the
neutron.
Validity
True
The nucleus is a vital part of the Rutherford-Geiger-Marsden
model.
The atom has a neutron.
Not True
In the Rutherford-Geiger-Marsden model electrons do not orbit
the nucleus
Timeline
Timeline
Marsden
Chadwick
Rutherford
Geiger