What are Cation Ions & Anion Ions?
A cation (pronounced cat-eye-on) is an atom or molecule that has gained a positive charge. This often happens in water, because of the unique nature of the water molecule which, like a magnet, has positive and negative ends (it is “polar”). An anion (pronounced ann-ion) is an atom or molecule that has a negative charge. A simple example of a cation and anion is table salt, NaCl or sodium chloride. Cations and anions are important in biology (in basic terms) because they neutralize charges, stabilizing other charged molecules or can be used to create electrical current/potential across a cell membrane (by building up a + or – charge) to send signals in the body. The size of an ion is approximately 1 micron or 1/1000 of a millimeter, which cannot be seen, even using a microscope.
