$2\mathrm{.}2-20$ Full Alternative Text

$2\mathrm{.}2$ Brass is an alloy of copper and zinc. Assume the weight percent composition of brass is $80\%Cu$ and $20\%Zn.$ Would you expect brass to be an

interstitial solution or a substitutional solution? Justify your answer based on the Hume$-$Rothery rules. $($See Fig. $1\mathrm{.}14$ and Table $2\mathrm{.}1.)$

$2\mathrm{.}3$ What is the difference in the definition of coordination number between metals and ceramics? Why are these two parameters different for the two

classes of materials?