An air sampler is used to collect particles less than $10m$ in diameter. The sampler is located

downwind from a steel plant. The accompanying data are for particulate samples collected on two

different days.

a$.$ For both samples, calculate the non$-$crustal abundance of $Fe,Mn,Cr$ and $Ni.$ Use $Al$ as the reference

element. Use the upper crust values.

b$.$ For particles emitted by the steel plant, $M\frac{n}{F}e=0\mathrm{.}009,C\frac{r}{F}e=0\mathrm{.}003,$ and $N\frac{i}{F}e=0\mathrm{.}002.$ Using the

non$-$crustal abundances of $Fe,Mn,Cr$ and $Ni,$ do emissions from the steel plant contribute to the

aerosol chemistry? Explain.

c$.$ If your answer to part $($b$)$ is yes, what percent of aerosol sample $1$ and aerosol sample $2$ is due to

emissions from the steel plant?

$Pb$ isotopic measurements of an aerosol sample give ${?}^{206}P\frac{b}{{?}^{204}}Pb=18\mathrm{.}673,{?}^{207}P\frac{b}{{?}^{204}}Pb=15\mathrm{.}667$ and

${?}^{208}P\frac{b}{{?}^{204}}Pb=38\mathrm{.}857.$ Calculate the ${?}^{206}P\frac{b}{{?}^{207}}Pb$ and ${?}^{208}P\frac{b}{{?}^{206}}Pb$ ratios for this sample.