What pressure must be applied to keep a gas at 750 torr and 300 k at a constant volume of 200 mL if the temperature is raised to 450 k

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.