How does density affect the melting point of water?

As a liquid is heated, its vapor pressure increases until the vapor pressure equals the pressure of the gas above it. Bubbles of vaporized liquid (i.e., gas) form within the bulk liquid and then rise to the surface where they burst and release the gas. (At the boiling temperature the vapor inside a bubble has enough pressure to keep the bubble from collapsing.) In order to form vapor, the molecules of the liquid must overcome the forces of attraction between them. The temperature of a boiling liquid remains constant, even when more heat is add.

7is b8 is d9 is c10 is a11 is d

The answer is 4 i don't know if its right let me see.