Which is a saturated solution? A）40g NH4Cl in 100g water at 50°C
B）2g SOz in 100g water at 10°C
C）52g KCl in 100g water at 80°C
D）120g KI in 100g water at 20°C

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole

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.