Ask Questions, Get Answers


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

$\begin{array}{1 1}(a)\;6.02\times 10^{20}& (b)\;0.502\times 10^{20} \\(c)\;5.02\times 10^{23}&(d)\;5.02\times 10^{20}\end{array} $

1 Answer

12g of C-12=$6.023\times 10^{23}$atoms
$10^{-3}(1 mg)$ of $C-12=\large\frac{6.023\times 10^{23}}{12}$$\times 10^{-3}$
$\Rightarrow 0.502\times 10^{20}$ atoms
Hence (b) is the correct answer.
answered Mar 25, 2014 by sreemathi.v

Related questions