Suppose that a piece of polystyrene insulation board has a thermal conductivity of k= 0.04 W/m. K.
In comparison, copper has a thermal conductivity of about 400
W/m. K. If you want to make a wall of copper
that provides the
insulation as a 4-cm polystyrene board, how thick does the
wall have to be (in meters)?
same
copper

Wish i can but don’t know this

D=m/v =57.9/3 = 19.3 g/cm^3

Those are different gas lawshere is a brief description of themcharles's law states that volume and temperature are directly proportional to each other as long as pressure is held constant.  boyle's law asserts that pressure and volume are inversely proportional to each other at fixed temperature.gay-lussac's law introduces a direct proportionality between temperature and pressure as long as it is at a constant volume.    source: