Mixing food coloring with water is an example of a chemical change true or false

False. The food coloring is dissolved in the water. This is just a physical change. For a chemical change to be observed, at least one product must be produced /reactant must be consumed.

The answer is d- principle of faunal succession.

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.