Question

A sphere has a negative charge of `6.4 xx 10^-7` coulombs. Approximately how many electrons must be removed to make the sphere neutral?

Answer 1

I got `4xx10^12` electrons

Explanation:

You know that one electron has a charge of `1.6xx10^-19C` so we need to remove:
`(6.4xx10^(-7))/(1.6xx10^(-19))=4xx10^12` electrons

Answer 2

`4*10^12`electrons

Explanation:

Since one electron has a charge of `1.6*10^-19C` we can simply take the overall charge of the sphere and divide it by the charge of a single electron to see how many electrons account for the overall charge. It would look like

`(6.4*10^-4C)/(1.6*10^-19C)`

Which would give us `4*10^12`electrons