What is the empirical formula of a 212.1g sample of a compound that contains 42.4g H and 169.7g C? What is the molecular formula of the compound having a molecular mass of 30.0g?

Joe shines white light into a bowl half full of water at an angle of incident of 27.5°. calculate the angle of refraction in the water given the indices of refraction for air and water are 1.00 and 1.36, respectively.

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

What best discribes the relationship between wavelength and frequency in a electromagnetic wave