A black dot used as a full stop at the end of a sentence has a mass of about one attogram. Assuming that the dot is made up of carbon, calculate the approximate number of carbon atoms present in the dot.

Explanation

Mass of carbon in dot = 1 attogram` =10^(-18)g`
Gram atomic mass of carbon = 12 g, i.e., 12 g of carbon contain `6.022xx10^(23)` atoms of carbon
`therefore 10^(-18)" g of carbon will contain carbon atoms"=(6.022xx10^(23))/(12)xx10^(-18)=5.02xx10^(4)" atoms"`