The scientist will add up the mass of the protons and mass
of the neutrons to come up with the approximate mass of atom because protons
and neutrons is what consist of the atoms. Therefore, in order to have the approximate
mass of an atom, adding the mass of protons and neutrons will give the result.
Hormones -- such as melatonin and cortisol; the former signals the body to go to bed, while the latter signals for the sleeping person to wake up -- are created by physiological changes.
Plants absorbs inorganic ions such as carbon dioxide by the process of gas exchange and water by the process of osmosis which converts into glucose and oxygen in the presense of sunlight and chlorophyll.Light is absorbed by the chlorophlasts present in green leaves.