Copper forms a substitutional solid solution with silver (known as sterling silver) where copper and silver exist in lattice point positions. If the densities of pure Cu and Ag are 8.96 and 10.49 g/cm3, respectively, compute the number of copper atoms required to create a 1 cm3 sterling silver alloy with 7.5 wt% copper.

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.

Answertransverse;

Bonding in the oxygen molecule does not obey the octet rule

The correct answer is b)