ERNEST RUTHERFORD& THE GOLD FOIL EXPERIMENTBy Jake Easton & James Lampmann

Birth

He was born on August 30, 1871 in Nelson, New Zealand

His parents were James and Martha Rutherford

He was one of 12 kids

Education

In 1887, he won a scholarship to Nelson College

From 1890 to 1893, he attended Canterbury College at the University of New Zealand

In 1894 he received an 1851 Exhibition Science Scholarship which allowed him to go to the Trinity College, Cambridge.

While he was there he studied as a research student under J.J. Thompson at the Cavendish Laboratory.

Jobs/ Career

In 1897 the MacDonald Chair of Physics at McGill University in Montreal, Canada became open. In 1898 he left New Zealand to take the job.

In 1907 he returned to England to become the Langworthy Professor of Physics at the University of Manchester

In 1919, he took a job as a Cavendish Professor of Physics at Cambridge.

Jobs/ Career Continued

After that he became: Chairman of the Advisory Council Department of Scientific and Industrial

Research Director of the Royal Society Mond Laboratory

at Cambridge A professor of Natural Philosophy at Royal

Institution, London

The Gold Foil Experiment

Rutherford did this experiment in 1910

He did it in order to: Learn more about

the structure of an atom

Confirm J.J. Thomson’s “plum pudding” model of an atom:

What He Accepted

Rutherford accepted that electrons were present in atoms and that they were negatively charged

He also accepted that there was something inside an atom that made it have a neutral charge and accepted the plum pudding model that had positively charged matter throughout

The Experiment

It was set up with a thick lead box with a small opening surrounding a source of heavy, alpha particles

A small beam of the particles was formed pointing at an extremely thin piece of gold foil (approximately 3.4x10-14m thick)

The Experiment Continued

He used a fluorescent rotatable detector which has a microscope and a screen coated with zinc sulphide to detect the alpha particles which he wrapped in a circle around the gold foil

The entire experiment was performed in an evacuated chamber in order to prevent scattering by the air molecules

Rutherford expected that all of the particles would go through the foil without any deflection

Results

When he performed the experiment, he received some interesting results

When the particles hit the foil, most went straight through, but some of the particles were deflected off at angles and even a few bounced right back off of the foil.

Conclusions

Since most of the particles went straight through, he concluded that most of the space in an atom is empty

Since some of the particles deflected or bounced straight back, he concluded that there must be a concentrated area that is positively charged

Also since only a very small amount of the particles were deflected, he concluded that the area of the positively charged particles must be very small

“Nucleus of an atom”

http://www.youtube.com/watch?v=Q8RuO2ekNGw

Rutherford’s Atomic Model

Was also known as the “planetary model”

It had 2 changes compared to the plum pudding model: A high concentrated area of

positively charges particles is central and very small compared to the rest of the atom (later named the nucleus)

The nucleus contains most of the atomic mass of the atom

Rutherford was the first to discover and prove the existence of positive central charge

Rutherford’s Atomic Theory

Most of the space in an atom is empty Almost all the mass of an atom is concentrated

in the center of the atom In the center of the atom there are positively

charged particles The negatively charged particles revolve around

the nucleus in different orbits The center region of the nucleus is extremely

small

Sources http://www.rutherford.org.nz/biography.htm http://www.nobelprize.org/nobel_prizes/chemis

try/laureates/1908/rutherford-bio.html http://physics.tutorvista.com/modern-physics/r

utherford-s-gold-foil-experiment.html