Cation is formed when an atom of mercury (Hg) loses two electrons.
If you are trying to observe a cell wall, you should look at a plant cell. There are only two different types of cells, which are plant and animal cells. The plant cell is the only one which contains a cell wall. Animal cells actually only have a <em>cell membrane. </em>
<span>Radioactive isotope, also called radioisotope, radionuclide, or radioactive
nuclide, any of several species of the same chemical element with
different masses whose nuclei are unstable and dissipate excess energy
by spontaneously emitting radiation in the form of alpha, beta, and
gamma rays.</span>