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Unit 1: Atomic Structure and the Periodic Table - Coggle Diagram
Unit 1: Atomic Structure and the Periodic Table
History of the Atom
John
Dalton
Described
atoms as spheres
Start of the 19th century
JJ
Thomson
Concluded that atoms weren't solid spheres
1897
Found the plum pudding model
Showed that atoms
contained smaller, negatively charged
particles called
electrons
Ernest
Rutherford
Alpha particle scattering experiment
Fired positively charged alpha particles
at a
gold sheet a few atoms thick
Expected the
alpha particles to pass through
or be
slightly deflected
1909
Some
defleceted more than expected
and
some deflected straight back
Concluded that
atoms are mostly empty space
and most of the
mass is concentrated in a positively charged nucleus
. A
cloud of negative electrons surrounds the nucleus
Niels
Bohr
Suggested the nuclear model had
electrons organised into shells
Each shell
is a
fixed distance away from the nucleus
The
shells orbit the nucleus
in fixed shells
James
Chadwick
Discovered the
neutron
1932
Group 1
Group 7
Group 0/8
Development of the Periodic Table
John
Newlands
Arranged by
atomic mass
Strict
on order
Put
elements in unmatching places
making his
table wrong
.
Dmitri
Mendeleev
Left gaps
and
predicted new elements
Ordered in
atomic mass
Was
not strict
on order