How many naturally occurring atoms are there?

The are 92 naturally occurring atoms, or elements. Two of these elements, Technetium and Promethium, are highly unstable and are sometimes not counted in the total number of natural atoms found on the earth.

There are more than 100 elements listed on the periodic table, but the first 92 are those that occur in nature. The remaining elements were made in laboratories. The two elements Technetium and Promethium have traits that cause them to occasionally be left out of the count of naturally occurring atoms.

• Technetium is unstable, has a very short half-life and, while it is found in extremely small quantities on earth, it is usually artificially produced in kilogram quantities.
• Promethium is found in uranium ore but never in quantities larger than a picogram per ton.