All of the chemical reactions that occur within a cell are collectively referred to as metabolism. This includes , which are those reactions that use energy and synthesize building blocks and macromolecules, and , which are the cellular reactions that break larger molecules into smaller molecules and release energy.

The water cycle increase the water content in the earth atmosphere

Aquantity of that isotope to decay to 1/2 of  its original value

Van der waals forces are temporary electromagnetic forces established between uncharged atoms. some neutral molecules, when close together, can become temporarily “charged,” as electrons move around the atom. water is a polar molecule, the side of the molecule that the hydrogens bond to being more positive, and the opposite side bound to the lone pairs of electrons being more negative. this means that it participates in dipole-dipole interaction (non-polar exhibits dispersion forces), and it has the capacity for hydrogen bonding.