Friday, October 19, 2012

Ions, Cations, and Anions

          Today, I will discuss the differences between ions, cations, and anions. From the last post about the structure of atoms, we know that an atom has the same number of electrons (negative charge) and protons (positive charge) to make the atom in an exact balance (neutral atom). What happens when an atom has extra electron or missing electron? The atoms are called ions.
So, when you are missing an electron or two, you have a positive charge called cation. When you have an extra electron or two, you have a negative charge called anion.

An example of creating cation.

A neutral lithium (Li) has 3 protons and 3 electrons, and it is missing an electron. Then we have 3 protons and 2 electrons. So lithium loses one electron to become a 1+cation.

An example of creating anion.
A neutral chlorine Cl has 17 protons and 17 electrons, and it is gaining one electron. Then we have 17 protons and 18 electrons. So, chlorine gained one electron to become a 1- anion.