ion exchangeable ion 2021-12-20T01:24:00Z Add an equivalence axiom to autopopulate this once we have ion exchange in as a process. An ion which is 1) adsorbed onto the surfaces of materials with an opposing charge, 2) are readily displaced by other ions, 3) may be displaced and absorbed by organisms. The exchangeable ion pool is the dominant storage pool for calcium, magnesium, and potassium ions. In soil, exchangeable ions are typically bound to the surface of clay and humus colloids.