Because that's where they come from. Coal, oil, and natural gas are the products
of dead dinosaurs rotting in the ground under great pressure for millions of years.
Density is the measure of a mass per unit volume of a material substance
density= Mass/volume
The unit of density is g/cm^3
Thus, there are 1.47 × 10^(23) molecules present in 122 grams of NO2.
Take the atomic mass of silicon and put it over one. Then set that equal to x over 4.8 x 1026. X will equal to the weight of silicon in grams.
