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Question
A student puts his signature with a graphite pencil. If the mass of carbon in the signature is 10-12 g, calculate the number of carbon atoms in the signature.
Solution
No. of atoms in 12 g C = 6.02 x 1023
∴ no. of carbon atoms in 10−12 g
= `(6.02 xx 10^23 xx 10^-12)/12`
= 5.016 x 1010 atoms
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