What types of examples sodium and calcium ions are?

If in case you are not familiar with what a cation is, this is known to be a positively-charged ion. This is the type of ion that will be attracted to the cathode ray during the process of electrolysis. There are different plant essential nutrients that are considered to be cations but there are also some anions that are present.

The fact that there are positive and negatively charged molecules are important because these will make sure that different chemical reactions will occur. If there are certain reactions that will not occur, it will be harder for living things to stay alive.