The document describes the development of atomic theory over time through several scientific models. It begins with Democritus' idea in the 5th century BC that all matter is made of indivisible atoms. The document then outlines models by John Dalton, J.J. Thompson, Ernest Rutherford, Niels Bohr, Erwin Schrodinger and Werner Heisenberg. Each model built on previous work and provided new insights about atoms, such as Dalton's billiard ball model, Thompson's plum pudding model, Rutherford's nuclear model, Bohr's planetary model, and Schrodinger and Heisenberg's quantum mechanical model describing electrons as waves. The document uses these historic theories to teach students

1. The
Development of
the Atomic
Theory
Teresita M. Perucho
Master Teacher I - Science

2. “
2

3. LEARNING COMPETENCY
Determine the number of protons,
neutrons, and electrons in a particular
atom
3

4. OBJECTIVES
➢ Infer the development of atomic theory ;
➢ Simulate and describe each atomic models ;
➢ deduce that scientific models may change over time
and
➢ Construct an atomic timeline using recycled materials.
4

5. Atomic Theories
5

6. 6
Choose the best answer
1. This diagram represents particles
in a ______________ state.
a. Solid b. liquid c. gas

7. 7
Choose the best answer
1. This diagram represents particles
in a ______________ state.
a. Solid b. liquid c. gas

8. 8
Choose the best answer
2. Particles are always moving.
a. True b. False

9. 9
Choose the best answer
2. Particles are always moving.
a. True b. False

10. 10
Choose the best answer
3. In which state of matter will there be the LARGEST space
between molecules?
a. Solid b. Liquid c. Gas

11. 11
Choose the best answer
3. In which state of matter will there be the LARGEST space
between molecules?
a. Solid b. Liquid c. Gas

12. 12
Choose the best answer
4. All matter is made up of tiny _______________
A. Energy
B. Particles (atoms and molecules)
C. bits
D. antimatter

13. 13
Choose the best answer
4. All matter is made up of tiny _______________
A. Energy
B. Particles (atoms and molecules)
C. bits
D. antimatter

14. 14
Choose the best answer
5. Which has a strongest Inter molecular Forces?

15. 15
Choose the best answer
5. Which has a strongest Inter molecular Forces?
a. Solid b. Liquid c. Gas

16. 16
ENGAGE
Can’t wait to go out and
have some fun?

17. Lets Take a Trip Through Time
17
Come with us in a
historical adventure!
Let’s find out the story
behind the small but
terrible ATOM.

18. ATOMIC THEORIES TIMELINE
18
NAME Democritus John Dalton
JJ
Thompson
Ernest
Rutherford
Niels
Bohr
Schrödinger
Heisenberg
TIME
FRAME
KEY
POINTS
MODEL

19. DEMOCRITUS
460 – 370BC
19
➢ There are various basic elements from
which all matter is made.
➢ Named the smallest particle of matter
“atomos” – not to be cut.
➢ Everything is composed of small atoms
moving in a void and capable of joining.
➢ Some atoms are round, pointy, oily, have
hooks, etc. to account for their properties.
➢ Ideas rejected by leading philosophers
because void = no existence

20. DEMOCRITUS ATOM
20
Wow !!!

21. JOHN DALTON
1766- 1844
21
Introduced his ideas in 1803
• Each element is composed of extremely
small particles called atoms
• All the atoms of a given element are
identical, but they differ from those of any
other element
• Atoms are neither created nor
destroyed in any chemical reaction
• A given compound always has the
same relative numbers and kinds of
atoms

22. 22
amazing !!!
John Dalton
Billiard Ball Model
1807

23. 23
Discovered electron
1897 – Cathode Ray
Experiment
• Plum Pudding model
1904
– Electrons in a soup of
positive charges
• Discovered isotopes
1913
J.J. Thompson
1856-1940

24. 24
amazing !!!
Cathode Ray Tube Experiment

25. 25
Chocolate
cookies!!!
JJ THOMPSON
Plum Pudding Model

26. Ernest Rutherford
1871-1937
26
➢ Atoms have dense , positive
nucleus.
➢ Atoms mass is mostly in the
nucleus .
➢ The nucleus has a positive
charge(Moseley)
➢ Electrons in fixed orbit

27. Alpha Particle Experiment
Gold Foil Experiment
27
A piece of gold foil was hit with
alpha particles, which have a
positive charge. Most alpha
particles went right through.
This showed that the gold
atoms were mostly empty
space. Some particles had their
paths bent at large angles. A
few even bounced backward.

28. 28
I often come
across this
symbol whenever
we talk about
science!!!
Ernest Rutherford’s Model
1909

29. “
29
We are learning so
much in this trip
I am having a blast
, excited to know
more about the
theories of atom

30. Niels Bohr
1885-1962
30
➢ Electrons orbit the positive nucleus in orbits
that have a set size and energy.
➢ The energy of the orbit is related to its size.
The lowest energy is found in the smallest
orbit.
➢ the change in an electron's energy as it makes
a quantum jump from one orbit to another
➢ Radiation is absorbed or emitted when an
electron moves from one orbit to another.

31. 31
It looks like
the solar
system!!!
Planetary Model
1913
Looks like
the model
of Sir
Rutherford.

32. Ernst/Erwin Schrödinger 1887-1961
Werner Heisenberg 1901-1976
32
➢ Electrons are in probability zones called
“orbitals”, not orbits and the location cannot be
pinpointed
➢ Electrons are present in a blurry “electron cloud”.
It is within this area that we derived the electron
configuration of an atom.
➢ – Electrons are particles and waves at the same
time
➢ Developed quantum numbers based on theories
of Einstein and Planck
Electrons have an intrinsic
property called spin, and an
electron can have one of two
possible spin values: spin-up or
spin-down. Any two electrons
occupying the same orbital must
have opposite spins.

33. 33
Wow !!!
Quantum Mechanical Model/Wave Mechanical model
1926
That is what
we call
ORBITALS.

34. ATOMIC TIMELINE
34
ELABORATE

35. ATOMIC THEORIES TIMELINE
35
NAME Democritus John Dalton
JJ
Thompson
Ernest
Rutherford
Niels
Bohr
Schrödinger
Heisenberg
TIME
FRAME
KEY
POINTS
MODEL

36. Who among you will
develop a
better theory and
win the Nobel
Prize?

37. EVALUATION
C
A B D E
Arrange the
following atomic
models in order and
identify who is the
physicist that
developed the
theory.
Schrodinger& Heisenberg ,
Erwin Rutherford , John
Dalton , Neils Bohr and JJ
Thompson

38. EVALUATION
C
A
B
D
E
JJ Thompson
John Dalton
Erwin Rutherford
Neils Bohr
Schrodinger&
Heisenberg

39. ASSIGNMENT
TO BE SUBMITTED ON FRIDAY
39
Construct an atomic timeline
using recycled materials
EXTEND

40. 40
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