When burning a cupcake under a calorimeter, your water went from 22oC to 82oC. You used 20ml of water. How much energy was absorbed by the water? (Specific heat of water is 1) q=mCΔT

B"hf and f-"  is the correct answer took the test on edgenuity and got it right     

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.