What is the density of a proton in an order of magnitude estimation? (in $kg/m^3$)

Mass and radius of the proton ${10}^{-27} kg$ and ${10}^{-15} m$ respectively.

For the diameter of the solar system$({10}^{13} m)$, how long does light take to transverse? (in ${10}^4$sec)

$c = 3\times {10}^8 m/s$.

An electron volt(eV) is a unit of energy equal to $1.6\times {10}^{-19}J$. An electron has kinetic energy of  $2.4eV$

How many joules is that?

An electron volt(eV) is a unit of energy equal to $1.6\times {10}^{-19}J$. An electron has kinetic energy of  $2.4eV$

What is the energy in eV of an electron that has an energy of $8.6\times {10}^{-18} J$?

What is an order-of-magnitude estimate mass of an apple? (in g)