Element Charges Chart – How to Know the Charge of an Atom

Element Charges Chart

Here is a chart of element charges and an explanation of how to find the charge of an element if you don’t know it. The difference between charge, oxidation state, and valence is explained, too. You can download and print these graphics and tables for references.

How to Find the Charge of an Element

There are four ways to find the charge of an element:

Element Valences 1-45

  1. Use the periodic table. The usual charge of an element is common to its group.
    Group 1 (Alkali Metals): 1+
    Group 2 (Alkaline Earth Metals): 2+
    Groups 3-12 (Transition Metals): Variable positive charges
    Lanthanide and Actinide Series: Variable positive charges
    Group 13: 3+
    Group 14: 4+ or 4-
    Group 15: 3-
    Group 16: 2-
    Group 17 (Halogens): 1-
    Group 18 (Noble Gases): 0
  2. Use a chart. Charts come from empirical data on the real behavior of elements, which may differ somewhere from the periodic table predictions. Here are two charts. The first shows common element charges, while the second shows all the element charges for the first 45 elements (most common charges in bold).
  3. For a single atom, the charge is the number of protons minus the number of electrons.
  4. Find the charge by balancing charge in a compound.

Assigning Oxidation Numbers

When we talk about the charge on an atom, it’s usually its oxidation number rather than its valence.

Charge, Valence, and Oxidation State

In many texts, the terms charge (or formal charge), valence, and oxidation number are used interchangeably. These three terms are related, but have slightly different definitions:

Confused? Usually, what you want to know is the oxidation state, which carries both a number and a positive or negative sign. For example, in HCl, both H and Cl have a valence of 1. One electron from each atom participates in chemical bond formation. But, hydrogen has an oxidation state of +1, while chloride has an oxidation state of -1. From the oxidation state, you know the charge (or vice versa). We write the charges of the atoms as H + and Cl – .

References