Science, Technology
Research Topic; Why do we think what we do?


History Of The Atom;


(18 December 1856 – 30 August 1940)

Who was Thomson?
J.J Thomson short for Sir Joseph John Thomson
was a scientist from Britain, but was born in 1856 in england.
In 1870 he studied engineering at University of Manchester.
J.J then became a professor of physics in 1884 and one of hes students was Ernest Rutherford who also became one of the famous scientist.
J.j first discovered the electron of isotopes and the invention of the mass spectrometer he is also known for the 'Plum pudding model'






(September 6, 1766 – July 27, 1844)

Who was Dalton?
John Dalton was a chemist and physicist from england who was born in cumbria in 1766.
Before johns discovery he was a private teacher of mathematics and chemistry.
In 1803 john developed the first atomic theory of matter.
which he then discovered colour blindness.



What did J.J think?
J.J thought that an electron was anegatively charged particle that was much smaller then the atom. he then thought that the tiny particles must have come from inside the atom. the tiny negatively charged electrons must have a postive charge around it.
and that the electrons carry no overall charge, so the charges must balance out.
What did Dalton think?
John thought that atom were like hard tiny balls. elements can't be broken down and that elements have its own different form in mass.
he also thought that the atoms of different elements could be identified by there differences in their weight. John then found out that all matter is composed of atoms, “atoms cannot be made or destroyed, all atoms of the same element are identical, different elements have different types of atoms, chemical reactions occur when atoms are rearranged and compounds are formed from atoms of the constituent elements”.(www.chemsoc.org/timeline/pages/1803.html)


Why did J.J think this?
J.J discovered the electron J.J was doing an experiment applying high voltages to gases at low pressure. He then noticed an interesting effect which he then decided to do experiments on the beams of particles in his tube. J.J found out that they were attracted to a positive charge. J.J concluded that they must be negatively charged themselves.
other experiments that J.J worked on showed 'that it would take about 2000 electrons to weigh the same as the lightest atom, hydrogen. He called the tiny, negatively charged particles electrons.'



Why did Dalton think this?
he thought this from his experiments and all his obsverations, dalton found out that atoms were the 'fundamental' building blocks o nature and it couldn't be split into pieces.
in the chemical reactions he did the atoms would rearrange themselves and combine with the other atoms in new ways.
John also found out that water contains an atom of hydrogen and an stom of oxygen and sumed up that the wight of the oxygen atom must be 5.6 times as large as the hydrogen atom. ^as the picture above shows^


(30 August 1871 - 19 October 1937)

Who was rutherford?
Ernest Rutherford was a very famous nuclear physicist.
Ernest was born in new zealand in 1871. he first went to Canterbury College,
University of New Zealand where he was the head of debating teams.
1895 ernest moved to enland to study at the canvendish laboratory.
he then decide to investigate on raioactivity.
Ernest did the orbital theory "of the atom through his discovery of
Rutherford scattering off the nucleus with his gold foil experiment" (http://en.wikipedia.org/wiki/Ernest_Rutherford)


What did rutherford think?
Ernest changed the results and suggested a different model for the atom, he thought Thomsons model could be right, and thought that the positive charge would be planted in a tiny volume in the center of the atom otherwise the alpha particles fired at the foil would never be repeeled back towards the source. this model above is showing the electrons orbited around the center of the atom.


Why did rutherford think this?
Ernest was doing an experiment ar manchester university about radiation they used positively charged particles as 'bullets' to fire at a piece of gold foil. they thought the paticles where going to barge thei way straight through the gold atoms, but they got a surprise ^diagram above^




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