Which term describes the movement if water molecules in and out of a cell

Gallium melts near room temperature and has one of the largest  liquid  ranges of any metal, so it has found use in high temperature thermometers.

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