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JJ Thompson
he found that they rays from a cathode ray bent when a magnet was held up to it. he concluded that these rays must be negatively charged and that they are in every atom and small than atoms. these are called electrons -
Rutherford
he aimed beams of alpha particles at a very thin sheet of gold fail. the results where that most of the times the particles would pass through but every so often they would bounce back. He figured out that atoms have a lot of empty space with a dense center, know known as the nucleus. -
Mosley and Darwin
He found that x-rays have simile properties of light. He diffracted x-rays through a crystal and their pattern would be symmetrical. with the help of Darwin, he found that the atoms in the crystal where neatly arranged into rows. He also found that the nucleus was a collection of positive particles, and the number of positive particles in each element was equal to the atomic number. due to this ending he was able to predict that there were 7 elements missing in the table. -
James Chadwic
He discovered that the neutron and that it was electrically neutral. -
Enrico Fermi
He fired neutrons at uranium and found that sometimes neutrons would chip a piece of the uranium nucleus, lowering the atomic number and turning it into a different element. he also observed that sometimes the neutron is absorbed by the nucleus and then spontaneously changes, which also creates a different element. he called these transuranic elements. -
Glen Seaborg
He created a new element from uranium 238 so that it could be more accessible in the making of atomic bombs, which he was also apart of creating