An atom or a molecule that has an electrical charge is called ion. There are two types of ions, negatively charged, called anions an - i - ons .

And positively charged, called cations cat-ions .

For some elements, it is possible to predict their electrical charge by their position in the periodic table (Figure 1).

Common ions indicated in position in periodic table. Positive charge for ions in column 1, on the left, except for hydrogen. Positive 2 charge for ions in column 2. Positive 1, 2 and or 3 charges for elements between column 2 and 3. Aluminium with charge positive 3 in column 3. Carbon with charge negative 4 in column 4. Elements in column 5 have negative 3 charge. Elements in column 6 have negative 2 charge. Elements in column 7 have negative 1 charge. No ions for noble gas column 8 on the far right. Generally, metals have positive charges between column 1 and 3. Non-metals have negative charges. Metalloids have negative charges and are found between metals and non-metals.

Figure 1: Ions in the periodic table and their charges