$($a$)$ In the deep space between galaxies, the density of atoms is as low as $106$ atoms$/$m$3,$ and the temperature is a frigid $3\mathrm{.}0$ K$.$ What is the pressure?

N$/$m$2$

$($b$)$ What volume $($in m$3)$ is occupied by $1$ mol of gas?

Consider applying the universal gas law in terms of the number of moles. Check units for consistency. m$3$

$($c$)$ If this volume is a cube, what is the length of its sides in kilometers?

What is the formula for volume of a cube? km