Journey Inside the Atom
Symbols of elements
Learn how the symbols of elements are written.
By 1869, about 69 elements were known. Today we know about 118, some of them made in laboratories.
Writing every element's full name gets slow, so chemists use symbols:
- In 1803, Dalton drew the first symbols as pictures (small circles with marks).
- In 1813, Berzelius suggested letters, taken from the elements' Latin names.
- Today, IUPAC (the International Union of Pure and Applied Chemistry) approves the names and symbols.
The rules:
- Usually the first letter, or the first two letters, of the name: H for hydrogen, Al for aluminium.
- The first letter is a capital; the second is small. Write Al, not AL. And Co (cobalt) is not CO, which means carbon and oxygen together.
- Sometimes another letter of the name is used: Cl (chlorine), Zn (zinc).
Some symbols come from other languages:
| Symbol | Element | From |
|---|---|---|
| Fe | Iron | Latin ferrum |
| Na | Sodium | natrium |
| K | Potassium | kalium |
| Cu | Copper | Latin cuprum |
| Ag | Silver | Latin argentum |
| Au | Gold | Latin aurum |
| Pb | Lead | Latin plumbum |
| Hg | Mercury | Greek hydrargyros |
| W | Tungsten | German wolfram |
"Why must everyone use the same symbols?" Imagine one scientist writes S for sodium and another writes Na. When an order for "S" arrives, which chemical should be sent? Shared symbols let scientists everywhere understand each other, whatever language they speak.
Element symbols: a capital first letter, a small second letter, and the same symbols everywhere in the world.
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