Question

A student puts his signature with graphite pencil. If the mass of carbon in the signature is 10^-12 g. Calculate the number of carbon atoms in the signature.

Answer 1

12g of carbon contains = 6.023 x 10²³ number of carbon atoms.
10^-12g of carbon will contain = `(6.023 xx 10^23 xx 10^(-12))/12`
= 0.5019 x 10¹¹
= 5.019 x 10¹⁰
So,the number of carbon atoms in the signature is 5.019 x 10¹⁰