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460
Greek philosopher, Democritus
That if you keep breaking something down that all that would be left is an atom that cant be broken any further
First person to come up with the atom theoryPeople thought that his idea was useless and incorrect
Around the year 460bc -
John Dalton
John Dalton was born in England in 1766
John Dalton said that matter and cant be broken down and he called them atoms
All mater is made of atoms -
Dimitri Mendeleev
He created the periodic table of elements which was his greatest achievement
He arranged 63 elements and placed them in groups using there atomic weights and they were in groups with other elements that are similar
He was born on the 8th of February 1834 -
J.J. Thomson
Born 18 December 1856
He was an English physistHe discovered the electron and made model of the atom and it was known as the ‘rasin in the pudding’
He knew that electrons had a positive charge and assumed that matter would have a positive charge. -
Max Planck
Max Planck who was a professor in theoretical physics. He found that if you vibrate atoms strong enough that they will glow and you can measure the energy in silent units.
He called the energy packets quanta
He was born on the 25th of April 1858 -
Hantaro Nagoka
He made a model of the atom and he based it on the Saturn rings that are stable.
The model had a very big nucleus and there were electrons surrounding the nucleus
He was born the 15th of august 1865 -
Ernest Rutherford
Ernest Rutherford was born in new Zealand in 1871
The expirements that he did made people think differently about the inside of a atom
He found out that there is a lot of space in gold atoms and that some parts of the atom were positively charged
The distance from where the electrons orbit to the nucleus depends on the energy they have -
Gilbert N. Lewid
Discovered the chemical bond with pair of electrons between to bonded atoms
He is more known for the electron dot diagrams which he started
He was born the 23rd of October 1875 -
Niels Bohr
discovered that electrons move around the nucleus but they don’t move the same way as the way that the plannets move around the sun
He was born 7th of October 1885 -
Erwin Schrödinger
Learn more about particle waves so you can make a model of an atom.His theory that the vibrations were like a string for a violin but they went around in circles
I was hard for people to make a picture of an atom because there is nothing in the world that compares to it.
He was born on august the 12th 1887 -
James Chadwick
Chadwick discovered the neutron in 1932
When he found the neutron other scientist started testing things on it. One scientist found that the neutron wasn’t a proton or electron pairing. Showing that he had found the third piece of the atom
He was born on the 20th of October 1891 -
Louis de Broglie
He thought that light is in particles and waves so atoms could behave like the waves and also contain light
Albert Einstein showed with his equations the way matter waves would behave if they existed
He was born the 15th of august 1892 -
Wolfgang
He predicted that electrons should spin around while it is going around the nucleus
The spinning electron can spin both ways
He was born on the 25th of April 1900 -
Enrico Fermi
Fermi split a nucleus in his earlier experiments but didn’t realise it
When a nucleus was split it would produce lots of energyFermi learned how to control the nuclear reaction then atomic bombs were constructed and nuclear power
He was born the 29th of September 1901 -
Paul Dirac
He predicted that there could be positively charged electron and nobody though at the time thought that it was possible
Carl Anderson performed expirements and discovered anti-electron which proved that Paul Dirac was right
He was born August 8th 1902
