4. compose
ELEMENT of ATOMS (cannot be divided into smaller particles)
DALTON’S MODEL OF AN ATOM:
(billiard ball model)
Atoms of the same Atoms cannot be
elements = same in destroyed Small
or Combination of atoms of
all their properties changed into atoms two or more elements
such as atomic ♥Hard Sphere
of any kind by forms a compound.
masses chemical reactions.
♥Indivisible

5. NIELS BOHR MODEL OF AN ATOM:
A small, positively charged nucleus surrounded by
electrons that travel in circular orbits around the
nucleus — similar in structure to the solar system,
but with electrostatic forces providing attraction,
rather than gravity.

6. THOMSONS’S MODEL OF AN ATOM:
(plum pudding model)
♥ Composed of electrons
♥ Surrounded by a cloud of positive charge to balance the
electron's negative charge, like plums surrounded by pudding.
♥ Electrons positioned throughout the atom, but
with many structures possible for positioning multiple electrons.
♥ Electrons were free to rotate within the cloud of positive substance

8. APPROXIMATELY Greek philosophers Leucippus and
500 BC Democritus proposed that all matter was composed of
small indivisible particles called atoms
Provided
John Dalton proposed
1803 AD the Billiard Ball Model
basic characteristics
of an atom
J.J Thomson
1897 AD
Discovered existence of
electrons and its
proposed the
presence in atoms
Plum Pudding Model
Albert Einstein
1905 AD showed that the frequency of light
was proportional to the energy
Later led to the
equation of E=MC2

9. Ernest Rutherford Provided information of
1909 AD proposed the Solar System
Model
the existence of a
nucleus in an atom
Ernest Rutherford Provided a number of
1911 AD proposed the Rutherford Model
with reference to a previous model
by Hantaro Nagaoka
essential modern features
including the nucleus
Niels Bohr
1913 AD
Provided a more
introduced the Bohr Model, accurate model of an
which was the expansion of the atom
work of Henry Moseley
Led to the current
Erwin Schrödinger
1925 AD proposed the Schrödinger
equation
atomic orbital models:
Quantum Mechanic model /
Electron Cloud model

10. ♥Dalton’s Atom Model :
http://www.juliantrubin.com/imagesc/dalton1.gif
http://en.wikipedia.org/wiki/John_Dalton
http://dl.clackamas.edu/ch104-04/dalton's.htm
♥Thomson’s Atom Model:
♥http://en.wikipedia.org/wiki/Plum_pudding_model
♥http://upload.wikimedia.org/wikipedia/commons/thumb/f/ff/Plu
m_pudding_atom.svg/348px-Plum_pudding_atom.svg.png
♥http://www.marcdatabase.com/~lemur/lemur.com/gallery-of-
antiquarian-technology/worthies/dalton-1200-scale1000.jpg
♥http://en.wikipedia.org/wiki/J._J._Thomson#Other_work
♥Bohr’s Atom Model:
♥http://cfa-www.harvard.edu/~sasselov/pic/Bohr.jpg
♥http://en.wikipedia.org/wiki/Bohr_model
♥Rutherford’s Atom Model:
♥http://en.wikipedia.org/wiki/Rutherford_model
♥Atom Timeline
♥http://atomictimeline.net/index.php
♥http://www.angelfire.com/mb2/atoms/
♥http://www.csmate.colostate.edu/cltw/cohortpages/viney/atom
history.html
♥Dotted Background Pattern:
http://3zehn.org
♥Other Resources:
♥Interactive Science 2 by Tho Lai Hoong and Ho Peck Leng