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Q & A: electron's negative charge

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Most recent answer: 10/16/2011
Q:
Are electrons really having negative charge ?
- ilyas (age 16)
j&k
A:

(published on 10/15/2011)

Follow-Up #1: Millikan oil drop experiment

Q:
In milkin's oil drop experiment we measure the charge of an oil drop ,and give that charge to electron , how electron has a charge of a oil drop?
- Ilyas (age 16)
Kashmir
A:
When you spray oil into the testing chamber some of the drops acquire a static charge. This process is similar to that when you comb you hair on a dry day.   Some of the drops have positive charge, some negative.   The number of charges on each drop can be different and so when you measure an individual drop you don't know the exact number.  But doing the experiment a number of times on several drops you find that the charges tend to cluster in integer values of a lowest one.   That lowest charge is presumably the charge of one electron. 

LeeH

(published on 10/16/2011)

Follow-up on this answer.