Question

A signature written with carbon pencil weighs 1 mg. What is the number of carbon atoms present in the signature ?

• A. $6.02\times 10^{20}$
• B. $0.502\times 10^{20}$
• C. $5.02\times 10^{23}$
• D. $5.02\times 10^{20}$

Answer 1

Answer: (B)

$12\text{gm}$ carbon contain = $6.023\times 10^{23}$

${\left(10\right)}^{-23}\text{gm}\left(\text{1mg}\right)=\frac{6.023\times {\left(10\right)}^{23}}{12}\times {\left(10\right)}^{-3}$

$=0.502\times 10^{20}$