Respuesta :
a = [tex]0.332 nm[/tex] for BCC crystal structure (given)
a = [tex]0.2978 nm[/tex] and c = [tex]0.4735 nm[/tex] for HCP crystal structure (given)
Volume of BCC = [tex]a^{3}[/tex]
Substituting the value:
Volume of BCC = [tex](0.332 nm)^{3}[/tex] = [tex]0.3659 nm^{3}[/tex]
Volume of HCP = [tex]a^{2}\times c\times cos 30^{^{o}}[/tex]
Substituting the values:
Volume of HCP = [tex](0.2978 nm)^{2}\times 0.4735\times cos 30^{^{o}} = 0.03637 nm^{3}[/tex]
Percentage change is calculated as:
Percentage change = [tex]\frac{Volume of HCP - Volume of BCC}{Volume of BCC}[/tex][tex]\times 100[/tex]%
Substituting the values:
Percentage change = [tex]\frac{0.03637 nm^{3} - 0.03659 nm^{3}}{0.03659 nm^{3}}\times 100[/tex]%
Percentage change = [tex]-0.6[/tex]%
The negative sign in percentage change indicates that there is a contraction during cooling.
