A piece of cork is placed on a triple beam balance. It has a mass of 0.75g. It is placed in a graduate which contains 10mL of water. The cork has to be pushed down to completely submerge it in the water. The water level rises to 13.1mL. What is the density of the cork?

Which of the following did you identify correctly

The mole ratio of hydrogen to ammonia is 3: 2.

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.

It is kept in an engine.hope it