An infrared lamp operating at a wavelength of 8.95 x10-7 m is used to heat up 2.50 ⋅ 102 g of water from 20.0°C to 90.0°C. Calculate the number of photons needed to do so, assuming that all of the infrared energy is converted into thermal energy.

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.