A Peek at Atomic Theory

1
A Peek at Atomic Theory

• Who is Hantaro Nagaoka?
• AND
• Who on earth is Ernest Rutherford?

By Amber Schwartz and Stephanie Hendricks
2
Hantaro Nagaoka

• Born August 15, 1865
• Born in Nagasaki, Japan
• Fun Fact!!!!!
• Not an extremely interesting man
• Professor of physics at the Imperial University
  in Japan

3
Nagaokas Atomic Theory

• Negatively cahrged particles orbit positive
  central charge
• Positive charge not spread out over entire atom
• At certain frequencies the ring structure of
  atoms would become unstable
• Destruction of rings that leads to atomic
  radiation
• Contribution made in in 1904 at the Imperial
  University in Japan

4
Ernest Rutherford

• Born August 30, 1871
• Born in Nelson, New Zealand
• Fun Fact!!!!
• Knighted in 1914

5
Rutherfords Atomic Theory

• A central positively charged nucleus surrounded
  by negatively charged orbiting electrons
• Most of mass of atom in nucleus
• Most of the rest of the atom empty space

6
The Gold Foil Experiment

• Fired atomic particles through thin gold foil
• Particles scattered when passed through foil
• Some particles deflected
• Particles detected using screens coated in zinc
  sulfide
• Flashed when hit by a particle

7
Gold Foil Experiment Cont.

• Some particles scattered at about 2 degrees
• 1 in 8,000
• Some particles scattered at more than 90 degrees
• 1 in 20,000

Discovery made in 1911 At Manchester University
8
Quiz Time!!

1. Where was Hantaro Nagaoka born?
2. What is Hantaro Nagaoka known for?
3. When was Nagaokas proposal for atomic structure
   published?
4. Where was Ernest Rutherford born?
5. What experiment is Rutherford known for?
6. What year did Rutherford perform that experiment?
7. What is one element of Ernest Rutherfords atomic
   theory?

9
Were You Right?

• Nagasaki, Japan
• Saturnian model of atomic structure
• 1904
• Nelson, New Zealand
• The gold foil experiment
• 1911
• The mass of the atom consists mostly of the
  nucleus
• Most of atom empty apace
• Central positively charged nucleus with negative
  orbiting electrons

10
References

• Baily, C. (2008, October 12). Hantaro Nagaoka
  (1904). In Atomic modeling in the early 20th
  century 1904-1913 (pg. 8) PDF file. Retrieved
  December 12, 2011, from Department of Physics,
  University of Colorado, Boulder website
  http//philsci-archive.pitt.edu/4232/1/Atomic_Mode
  ling_101208.pdf
• Campbell, J. (2011). Rutherford- a brief
  biography. Retrieved December 13, 2011, from John
  Campbell website http//www.rutherford.org.nz/bio
  graphy.htm
• Ernest Rutherford- Boigraphy. (n.d.). Retrieved
  December 12, 2011, from Nobel Foundation website
  http//www.nobelprize.org/nobel_prizes/chemistry/l
  aureates/1908/rutherford-bio.html
• Ernest Rutherford facts. (n.d.). Retrieved
  December 12, 2011, from Science Kids website
  http//www.sciencekids.co.nz/sciencefacts/scientis
  ts/ernestrutherford.html
• The gold foil experiment (Ernest Rutherford).
  (n.d.). Retrieved December 13, 2011, from
  http//chemed.chem.purdue.edu/genchem/history/ruth
  erford.html
• Nagaoka, Hantaro. (n.d.). Retrieved December 12,
  2011, from HighBeam Research website
  http//www.encyclopedia.com/doc/1G2-2830903102.htm
  l
• Rutherford - atomic theory. (n.d.). Retrieved
  December 12, 2011, from http//www.rsc.org/chemsoc
  /timeline/pages/1911.html