How many grams of magnesium, Mg, would contain the same number of atoms as 207.2 g of lead, Pb?

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.

If one fission reaction of a uranium-235 atom produced two neutrons, how many neutrons would be released if the chain reaction occurred three more times?

The vapor pressure of ethanol is 1.00 × 102 mmhg at 34.90°c. what is its vapor pressure at 61.61°c? (δhvap for ethanol is 39.3 kj/mol.)