# Electrons in GRAMS

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.

diazona
Homework Helper

How about keeping a couple more digits in that 4.79e27?

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

its a quiz online, tells me whether im 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.

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.

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

Stay Up
-1-

Borek
Mentor

tried that and got 4.366556698 and was still wrong even using only 3 sig figs
I understand you have tried 4.37?

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 !!