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Robert Andrews Millikan's Experiment
R.A. Millikan's Experiment
Robert Millikan's Experiment
The Experiment of Millikan, Robert
Electronic Supersonic
100
How did Millikan calculate the mass of a single electron?
Millikan divided the charge of an electron by its charge to mass ratio.
100
Why did Millikan redo his experiment numerous times, changing the strength of the x-rays each time?
Millikan changed the strength of the x-rays each time so a different number of electrons would jump onto an oil drop each time, which changed each drop's charge.
100
How did Millikan charge the 2 metal plates in his machine?
Millikan attached a battery to the machine and applied an electric voltage, which charged one plate negatively and the other positively.
100
What was the function of an atomizer?
An atomizer sprayed droplets of oil into the top chamber of Millikan's apparatus.
100
What English physicist used a cathode ray tube to determine the ratio of electric charge to the mass of an individual electron?
J.J. Thomson
200
What value did Millikan finally obtain for the mass of a single electron?
9.10 x 10^-28 grams
200
After Millikan obtained numerous values for the oil drops' charges, what did he do with all this data?
Millikan solved for the least common multiple of all the values, which he determined to be the charge on a single electron.
200
How did Millikan suspend the oil drops in mid-air in his apparatus?
Millikan adjusted the electric field so that the electromagnetic force would balance the force of gravity on the oil drops.
200
Why did Millikan measure the terminal velocity through the microscope?
The terminal velocity allowed him to calculate the mass of each oil droplet through a formula.
200
What number was calculated to be the ratio of electric charge to the mass of an electron in coulombs/gram?
-1.76 x 10^8 C/g
300
What was Robert Millikan's middle name?
Andrews
300
What was the exact value of Millikan's least common multiple (AKA the charge of an electron)?
-1.6 x 10^-19 Coulombs (C)
300
Explain the equation Millikan used to calculate the charge on an oil drop.
The weight of an oil drop is equal to the charge on the drop multiplied by the applied electric field. Millikan measured the voltage and the weight, so he could solve for the drop's charge.
300
How did the oil drops become ionized?
X-rays were introduced to the lower chamber, ionizing the air particles and transferring electrons to the oil droplets.
300
By using J.J. Thomson's charge to mass ratio and the charge of an individual electron, what was Millikan able to calculate?
the mass of an electron