Dark interstellar gas clouds contain so many dust grains that starlight cannot pass through, even though the dust grains are tiny and the spaces between them are quite large by earthly standards. A typical dust grain has a radius of about 10^-7 meter and a mass of about 10^-14 gram.
C. Estimate the total surface area the cloud covers, assuming that its matter density is like that of a typical molecular cloud, about 10^-21 g/cm^3 . (Hint: First calculate the cloud's volume from its mass and density, then determine the cloud's radius using the formula for the radius of a sphere R= (3xVolume/4?)^(1/3) .) State your answer in square light-years.
C. Estimate the total surface area the cloud covers, assuming that its matter density is like that of a typical molecular cloud, about 10^-21 g/cm^3 . (Hint: First calculate the cloud's volume from its mass and density, then determine the cloud's radius using the formula for the radius of a sphere R= (3xVolume/4?)^(1/3) .) State your answer in square light-years.