By:
David Eastwood
Mark Kynock
Marie Wieczorek
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Born: March 22, 1868 in Morison, Illinois.
Died: December 19, 1953 in San Marino, California.
Second son of Reverend Silas Franklin Millikan and
Mary Jane Andrews.
His favourite undergraduate subjects were Greek and
Math.
Obtained a Masters in Physics.
Was appointed Fellow in Physics at Columbia
University.
Got his PhD. In 1895 for “research on the polarization
of light emitted by incandescent surfaces - using for
this purpose molten gold and silver at the U.S. Mint.”
He has been awarded the Comstock Prize of the
National Academy of Sciences, the Edison Medal of the
American Institute of Electrical Engineers, the Hughes
Medal of the Royal Society of Great Britain, and the
Nobel Prize for Physics 1923. He was also made
Commander of the Legion of Honour, and received the
Chinese Order of Jade.
 By 1916 Robert Millikan found that the magnitude of an
electrons charge was 1.6 x 10-19 C. With this, Millikan set
out to prove that Einstein’s thoughts on quantum nature of
light were wrong.
 Millikan made photoelectric tubes with emitters made of
many metals. He measured the stopping potential for
different frequencies, for each metal that he used. Using
his experimental charge of an electron, he calculated the
values for the maximum kinetic energy for every frequency
using E=qV
 In Millikan’s case
E was the max kinetic energy of the potoelectrons
q was the charge on an electrons
Which made the equation Ek(max)= eVstop
Millikan then graphed his results
 To relate the graphs of Ek(max) versus f to Einstein’s, he
solved for Ek(max)
Ek(max)= hf- W
Notice how the equation relates to the equation of a straight
line y=mx+b
Comparing the two equations, Planks constant, h, is the
slope, m, and the Work function, W, is the y intercept, b.
 eV – electron volt is needed when using the
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photoelectric formula. The electron volt is the energy
gained by one electron as it falls through the potential
difference of one volt and it is used because the Joules
that are used in the photoelectric effect are very small
therefore the eV was developed.
E=qV
1eV=(1e)(1V)
1eV=(1.60x10-19C)(1V)
1eV= 1.60x10-19 J
 The stopping potential for
electrons emitted from the
surface of lead is 3.57V. What
is the frequency of the photons
that are striking the metal
surface?
E=qV
V= f
hf0=W or f0=W/h
Table 18.1 on p.853
 1. The frequency of the photons is 1.1 x 10^15 Hz. What
is the most likely type of surface that the photons are
striking?
 2. A metal has 1.258 x 10^-13 C and a stopping potential
of 0.547V. How many electron volts are there in this
metal?
 3. If the stopping potential is 5.68 x 10^6V and the
frequency is 8.62 x 10^12 Hz, what is the wavelength?
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http://www.google.ca/imgres?imgurl=http://reichchemistry.wikispaces.com/file/view/millikan.jpeg/31451689/millikan.jpeg&imgrefurl=http://reichchemistry.wikispaces.com/Slaney.Camara.atomictimeline&usg=__Yws8Cwa_-gSi7CAxxHmLDGsQIg=&h=300&w=248&sz=46&hl=en&start=0&zoom=1&tbnid=549r1z0iuALmM:&tbnh=147&tbnw=140&ei=5Yi9TbPJFaLz0gH9iYCwBg&prev=/search%3Fq%3Drobert%2Bmilli
kan%26hl%3Den%26sa%3DX%26biw%3D1419%26bih%3D715%26tbm%3Disch%26prmd%3Divnso&it
bs=1&iact=rc&dur=156&page=1&ndsp=36&ved=1t:429,r:1,s:0&tx=63&ty=104
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http://nobelprize.org/nobel_prizes/physics/laureates/1923/millikan-bio.html
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http://www.google.ca/imgres?imgurl=http://www.capitolpride.org/images/symbol_lambda.png&img
refurl=http://www.capitolpride.org/glbt_symbols.shtml&usg=__0TlmncHjJOfQoutNvuJdQzOCVoQ
=&h=400&w=240&sz=8&hl=en&start=0&zoom=1&tbnid=xcvfiUyRoPn3KM:&tbnh=143&tbnw=86&ei=
AJK9TY_xOuia0QG42u2yBg&prev=/search%3Fq%3Dwavelength%2Bsymbol%26um%3D1%26hl%3D
en%26sa%3DN%26biw%3D1436%26bih%3D715%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=123&vp
y=32&dur=772&hovh=290&hovw=174&tx=68&ty=191&page=1&ndsp=28&ved=1t:429,r:0,s:0
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2003 McGraw-Hill Ryerson Physics Textbook
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1989 Cutnell-Johnson Second Edition Physics Textbook
Physics Fourth Edition, D.C Heath and Company, Lexington, Massachusetts, Toronto