he study of Earth's atmospheric ozone and the effect of chlorofluorocarbons on ozone is an example of .

Particle exchange energy though elastic collision , hope this .

Hope the image of the frequency formula

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf   

Contained in chromosomes which are located in the nucleus of the cell.