Answer
The density of proton would be greater than that of electron
Work Step by Step
We know that
$Density=\frac{mass}{Volume}$
According to given condition if the volume of a proton were similar to the volume of an electron then the density of the proton would be greater because the mass of proton $(9.109\times 10^{-31})$ is greater than the mass of electron $(1.673\times 10^{-27})$.
