What is the net charge of a metal sphere after adding 7.0 x 10^13 electrons?

[MD2000]

A metal sphere has a charge of +5.0 µC. What is the net charge after 7.0 x 10^13 electrons have been placed on it?

What I tried was to convert the number of electrons to a charge by multiplying it by (1.6 x 10^-19)..and then adding that to the 5..from which I got 16.2..am I takin the right approach?

 

[Astronuc]

The metal sphere has a +5 µC charge, which means a deficit of electrons.

Add to this 7.0 x 10¹³ electrons, each of which has a charge of -1.6022 x 10^-19 C.

So the total charge of electrons is 7.0 x 10¹³ * -1.6022 x 10^-19. Note that the electron charge is negative.

 

[therealkellys]

I'm not sure how you got 16.2. Did you take into account the charge of electrons (-)? Also, make sure to check the units of the metal sphere.

Aw, astronuc, beat me to it

 

[MD2000]

Ahh..I completely forgot the negative..thanks astronuc