The number of atoms of an element present in one molecule of a substance

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this

Estimate the molar mass of the gas that effuses at 1.6 times the effusion rate of carbon dioxide.

How might this scientific phenomena be explained? a paper clip floats on water.