Calculating Mass of Electrons in GRAMS

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Electrons in GRAMS :(

Homework Statement



Part1:

A sample of electrons is found to have a total charge of -7.68 x 10^8 C.
How many electrons are in this sample ?
===================================
Part 2 says:

What is the mass of the above sample of electrons in grams ?


Homework Equations


1 electron mass = 9.10938188 × 10^-28 grams]


The Attempt at a Solution



for part 1 My answer was 4.79e27. And its CORRECT

for part 2 i keep getting 4.36 as an answer but its wrong.

I used [1 electron mass = 9.10938188 × 10^-28 grams]

and multiplied that by my answer for part 1.

PLEASE HELP, Thanks.
 
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diazona said:
How about keeping a couple more digits in that 4.79e27?

tried that and got 4.366556698 and was still wrong even using only 3 sig figs

Help please
 


How are you checking your answer?
 


PhaseShifter said:
How are you checking your answer?



its a quiz online, tells me whether I am correct or incorrect

Any more help guys ?
 


Hmm, multiple choice or one of those annoying computer quizzes that counts an answer wrong when it's misspelled, has a space left out, etc?

The math looks OK to me, it could just be the quiz expects something like spelling out units rather than using the abbreviation.
 


PhaseShifter said:
Hmm, multiple choice or one of those annoying computer quizzes that counts an answer wrong when it's misspelled, has a space left out, etc?

The math looks OK to me, it could just be the quiz expects something like spelling out units rather than using the abbreviation.


no its fill in the blank, but it specifically says "IN GRAMS" and "WITHOUT UNITS" and since the first part I got right with only 3 sig figs, I thought that was my problem here, but it was still wrong.

Help please.
 


Sorry I got the same answer as you, must be something wrong with the quiz

Stay Up
-1-
 


deteam said:
tried that and got 4.366556698 and was still wrong even using only 3 sig figs

I understand you have tried 4.37?
 


Borek said:
I understand you have tried 4.37?

ya I got the problem fixed it wasn't my answer that was wrong it was a technical error.

Thanks for the help guys !