Answer : The crown is not made of pure (100%) gold.
Explanation :
Formula used :
[tex]\frac{W_{apparent}}{W_{actual}}=1-\frac{\rho_w}{\rho_c}[/tex]
where,
[tex]W_{apparent}[/tex] = apparent weight of the crown in water = 4.50 N
[tex]W_{actual}[/tex] = actual weight = 5.00 N
[tex]\rho_w[/tex] = density of water = [tex]1.00g/cm^3[/tex]
[tex]\rho_c[/tex] = density of crown = ?
Now put all the given values in the above formula, we get:
[tex]\frac{4.50N}{5.00N}=1-\frac{1.00g/cm^3}{\rho_c}[/tex]
[tex]\rho_c=10g/cm^3[/tex]
Density of crown < Density of gold
[tex]10g/cm^3<19.32g/cm^3[/tex]
Thus, the crown is not made of pure (100%) gold.