Transcript Thomson’s Atomic Model

Thomson’s Atomic Model
Varsha Sharma & Leanna Ng
Block H
Sir Joseph John Thomson
1856-1940
• Was a physics
professor at
Cambridge University
• Was Ernest
Rutherford’s teacher
• Won the Nobel Prize
for Physics in 1937
•
Sir Joseph John Thomson
What Did he Discover?
• 1897, atoms made of
evenly distributed
electrons in a positive
jelly
• Called electrons
“corpuscles”
• Also believed that
Cathode rays are streams
of electrons
• Invention of mass
spectrometer
• Discovery of isotopes
•
Thomson’s Model of the Atom
What Common Things is his Atomic Model Compared to?
•
•
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Plum pudding
A Blueberry muffin
A Chocolate chip
cookie
In the picture:
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•
“chocolate chips” are
electrons
“dough” is positively
charged
How did Thomson’s Model Connect to Past Models?
• Thomson disproved that
atoms had no internal
structure and are
indivisible
• Discovered method for
separating different kinds
of atoms and molecules
by using positive rays
•
Democritus’ Model of the Atom
How did Thomson’s Model Connect to Future Models?
• Ideas about separating
atoms and molecules led to
discovery of isotopes
• Discovery of electrons led to
Rutherford’s model, which
disproved Thomson’s model
• Discovered positively
charged nucleus surrounded
by electrons
• Nucleus made of neutrons
and protons
• Electrons around nucleus
made atom neutrally
charged