Convert 420.0 k to °C

How to convert a density of 0.791g/cm3 to lb/ft3

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.