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Science 9.1

Terms in this set (18)

Democritus
Greek philosopher that said all matter is made of tiny particles called atoms - wasn't accepted
Aristotle
A greek philosopher that said all matter is made of earth, fire, water, and air
Dalton believed atoms were
a solid sphere
Atoms cannot be
subdivided, created, or destroyed
Atoms cannot
be converted into atoms of another element
Atoms are identical to
each other
Atoms are different from
atoms of another element
Atoms combine in
specific amounts
definition of atom
Smallest particle of an element that represents that element
Size of an atom
very small-cannot be seen with the human eye or regular microscopes
7.6 trillion make up the period in our textbook
what are atoms made of
protons, neutrons, electrons, and quarks
location of empty space in an atom
in between the nucleus and electrons
JJ Thomson's atomic model
-Thomson discovered negative particles in atoms called electrons.
-the green ray in the cathode tube was pulled towards the positively charged plates placed on either side of the tube
• "plum pudding" model-electrons (negatively charged subatomic particles) are scattered about the atom like plums in a plum pudding (or today we would say like "bananas in a banana pudding").
• The "pudding" part of the atom was composed of positively charged material.
Ernest Rutherford
Discovered the nucleus
gold foil experiment - some alpha particles passed straight through the gold foil and some hit the nucleus ad bounced back; the screen around the experiment beeped when the bounced back particles hit it
nuclear model - all electrons are the same distance away from the nucleus
What did James Chadwick discover?
neutron
How was Niels Bohr's Model different than Rutherford's?
electrons were placed in energy levels that were different distance from the nucleus
Electron Cloud Model
model of atom in which the electrons seem to form a cloud as they move around the nucleus - the cloud gets thicker where the electrons are predicted to be then farther apart where there are possibilities of electrons
six basic types of quarks
up
down
charm
strange
top
bottom
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