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21 Cards in this Set
- Front
- Back
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All matter is made up of tiny indivisible particles called atoms |
John Dalton |
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Who first came up with the theroy that matter can be divided into smaller poeces until they reach a single indivisible particle. |
Democritus |
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What did Democritus propose about atoms |
.of different sizes .in constant motion .seaparated by empty spaces |
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What did Aristotles theroy support |
Mattet is made up of fire earth water and air. |
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All atoms of an element are identical |
John Dalton |
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Atoms contain negatively charged electrons |
J.J Thomson |
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Atoms from different elements are different |
John Dalton |
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Atoms are arranged to form new substances in chemical reactions, but they are never created or destroyed |
John Dalton |
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Since atoms are neutral the reat of the atom is a positively charged sphere |
J.j Thompson |
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Neagativley charged electrons are distributed thorough out the atom |
Jj. Thompson |
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Goldfoil experiment |
Ernest Rutherford |
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What did E.R do |
Her shot positively charged particles at a piece of gold foil. |
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What did he expect in his experiment |
he thought the y would pass through and some would be deflected at small angles |
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What really happened |
Some went through but some deflected at very large angles |
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the Centre of an atom has a positive charge. Its called a nucleus |
Ernest Rutherford |
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What did the nucleus do in er experiment |
Made some particles bounce back |
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the nucleus has most of the a t oms mass but occupies a small space |
Good |
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Who found the protons |
Er |
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Who found electrons |
Jj thomson |
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What particle can penetrate and disintegrate atom with extraordinary power |
Neutrons |
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What particles have zero xharge |
Neutrons |
