Question

A signature in carbon pencil weighs 10⁶ ng. What is the number of carbon atoms present in the signature?

a.6.022 x 10—²⁰

b.5.02 x 10¹⁹

c.5.02 x 10²⁰

d.6.02 x 10²⁰​

Answer 1

Answer:

Answers

Correct option is

D

0.502×10

20

1 mg=1×10

−3

g

The number of carbon atoms present in the signature =

12 g/mol

1×10

−3

g

×6.023×10

23

atoms/mol=0.502×10

20

atoms

Answer 2

Answer:

Now the molar mass of carbon is 12gmol−1 . So we can say that 12g of carbon contains Avogadro's number of particles. Where n is the number of carbon atoms. So the answer of the above equation comes out to be 0.502×1020 .