It depends on the atom, or more specifically, on the size of its nucleus. There is a competition between the electrical repulsion of the protons (that drives the nucleus apart) and the attraction of the protons and neutrons (due to chromodynamics). For nuclei above a certain size, the repulsion tends to win
Co2 will dissolve in water if water is saturated with Co2 first then it will absorb some of CO2 it appear as less is absorb that was actually the case . this would make it appear as present of CACO3 is in original sample is lower than it will be too low