How much energy does the em radiation have?

The answer is that different frequencies of EM waves carry different amounts of energy. The energy of an EM wave depends on its frequency. High-frequency, short-wavelength EM waves have more energy than low-frequency, long-wavelength waves. A high-frequency EM waves carries a lot of energy, so it has the possibility of damaging living tissue. But low-frequency wave carries much less energy, and is safer.

 

Answer (b) supersaturation;

Vander waals forces are inter molecular bonds that exist within molecules of the same substance. a water molecule is made up of oxygen and hydrogen atoms which share electrons between each other. the vander waals forces are forces that exist between multitude of different  molecules of water. dipole dipole forces is the type of vander waals force that exist in water. the oxygen atom which is more electronegative pulls the shared electron closer to itself thus generating a partial negative charge while the hydrogen acquire a partial positive charge. these two different charges causes attraction to occur in water molecules.