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his mother Martha Thompson was a school

� Ernest Rutherford was born on

30 August 1871 in Spring grove near

Nelson,Newzealand. His father, James

Rutherford was a farmer from Scotland and

his mother Martha Thompson was a school

teacher from England.

Ernest was the fourth of

the 12 children. He was blessed with high

intelligence and talent for sports.

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time working as a school teacher. He then won a

He attended high school at Nelson college, where his boarding fees were funded by a scholarship. In 1893 he graduated with first class honors in Mathematics and Physical science. In 1895 he obtained a bachelors degree in Chemistry and Geology from Canterbury college and spent short time working as a school teacher. He then won a scholarship that enabled him to study overseas. He decided to go Cambridge in the United Kingdom to work in J.J Thomson's laboratory. Rutherford's research works remarkably impressing Thompson enormously.

Words of J.J Thomson about Rutherford “I have never had a student with more enthusiasm or ability for original research than Mr. Rutherford”

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In 1907 after nine years at Mc

And so in 1898 Rutherford

sailed to Canada taking up a professorship

aged 27.At Mc Gill he carried out the work

which led to his Nobel prize on 1908.

In 1907 after nine years at Mc

Gill Rutherford sailed back to the UK,where

he had been appointed to the university of

Manchester chairs of Physics.

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following

� Discovery of alpha and beta radiation

Starting in 1898 Rutherford studiedradiation emitted by Uranium.He discovereddifferent types radiation with the help of his co-worker Frederic Soddy and he came to the

conclusions.following conclusions.

1. Alpha particles are atomic in nature.

2. Alpha particles are Helium ions carrying

2+ charge.

3. Alpha particles are produced by the

disintegration of larger atoms.

4. When large atoms emit alpha particlesthey become

slightly smaller atoms.

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� In 1907 Rutherford discovered that radio

Rutherford coined the terms alpha,beta and gamma for the three most common types of nuclear reaction.We still use these terms today.

� In 1907 Rutherford discovered that radio active elements have half-lives, he coined the term half-life period to that phenominon.Rutherford was awarded the Nobel prize on 1908 in chemistry for his investigations into the disintegration of the elements and the chemistry of radio active substances.

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experiment in which he demonstrated that

� DISCOVERY OF ATOMIC NUCLEUS

Ernest Rutherford overtuned

Thomson's atom model(plum pudding

model)with his well-known Gold foil

experiment in which he demonstrated that

the atom has a tiny massive nucleus.

Rutherford designed an experiment

to use alpha particles emitted by a radio

active element as probes to the unseen

world of atomic structure.

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thickness.

� Rutherford beamed alpha particles through

gold foil and detected them as flashes of

light or scintillation on a screen.

� The Gold foil was only 0.00004 centimeter

thickness.

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Some even bounced back toward the source.

� During the experiment,most alpha particles

were observed to pass straight through the

gold foil.

� A few were scattered at large angles.

� Some even bounced back toward the source.

Rutherford explained the effect by

proposing a new model for the atom

replacing the plum pudding model of his old

mentor J.J Thomson.

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protons.

� most of the mass and all positive charges of an atom is concentrated in a very small region called “nucleus”.

� The positive charge on the nucleus is due to protons.

� The nucleus is surrounded by negatively charged electrons they revolve around the nucleus.

� Total negative charge on the electrons is balanced by the total positive charge on the nucleus.ie,nucleus is electrically neutral.

� Most of the space inside the atom is empty.

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and also about their energies.

� Rutherford model failed to explain the

stability the atom.

� It does not tell anything about the

distribution of electrons around the nucleus

and also about their energies.

� Rutherford's model failed to explain the

existence of certain lines in the spectrum of

Hydrogen.

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DISCOVERY OF PROTON

� DISCOVERY OF NUCLEAR REACTIONS

In 1919 he converted nitrogen atoms into Oxygen atoms by bombarding Nitrogen with alpha particles. This nuclear reaction was initially written as,

14N + α 17O +1H

� DISCOVERY OF PROTON

Finding hydrogen produced in the nuclear reaction above,Rutherford began to suspect that the hydrogen nucleus may actually be a fundamental particle,a building block of all atomic nucleus.

He formalized this in 1920 by giving this particle a name: the “proton”. the first nuclear reaction could now written as,

14N +α 17 O+proton

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nucleus ,the repulsion of the positively

� PREDICTING THE EXISTANCE OF NEUTRON

Rutherford carried out calculations of

the stability of atomic nuclei. He found that

unless some particle were added to the

nucleus ,the repulsion of the positively

charged protons apart.In 1920 he named this

hypothetical particle the ‘neutron’.

James Chadwick ,Rutherford's

assistant director of research, discovered the

neutron in 1932,proving its existence by

experiments.

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� 1914-Knighthood for the advancement of

� 1908-Nobel prize in chemistry for his

investigations into the disintegration of the

elements and chemistry of radio active

substances

� 1914-Knighthood for the advancement of

science.(he is the first Baron of Nelson

&Cambridge)

� In 1919,with J.J Thomson retirement as the

Cavendish professor of experimental physics,

Rutherford his old student was appointed as

his replacement.

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Rutherford was a direct no-non sense man, who spoke his mind. He was not overly concerned with his appearance; some people mistook the great scientist for a farmer!

He was well-known for his limitless reserves of energy and enthusiasm, which left a number of his workers exhausted.exhausted.

In 1900, Rutherford marry Mary Georgina. They had one child, Eileen Mary born in 1901.

Ernest Rutherford was died due to intestinal paralysis at the age 66 on October 19,1937.His ashes were buried in the nave of Westminster Abbey, joining other science greats such as Newton, Lord Kelvin, Charles Darwin etc…

ELEMENT 104 IS NAMED RUTHERFORDIUM IN HIS HONOR.