My house in italy comes with a fireplace that heats the radiators what heats the hot water?.

Its strengthits conductivity of heat and electricity its shiny colourmalleable and ductility

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water

Idon't mean to be a smart alec, length of atoms' bonds is the simplest way to define it.

Um i think answer is a