Idon’t understand the difference between ammonium and ammonium ion. i possibly did 9.a) correct but part b is a bit tricky

You can still be friends with each other. you don't have to date since he likes someone else. just stick to being friends for now

The size is 8inches if ur a girl

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.