Chemical Symbols
Science: KS3, topic 2.3.5
Chemical Symbols
Instead of writing the element or compound name every time, scientists have symbols for each element, which makes writing about them easier.
Chemical symbols
- Every element has a symbol, which is shown on the periodic table.
- Some symbols are just one letter, some are two. The first letter is always a capital. If there is a second letter, it is always lower case.
- E.g.
- Hydrogen is ‘H’.
- Helium is ‘He’.
- Magnesium is ‘Mg’.
- Sulfur ‘S’.
- Lithium is ‘Li’.
Odd symbols
- Usually, the chemical symbol relates to the element's name. But some are completely different.
- E.g.
- Potassium is ‘K’.
- Sodium is ‘Na’.
- Gold is ‘Au’.
- Copper is ‘Cu’.
Paired atoms
- Some gas elements have atoms that travel as single atoms, whereas other gas elements have atoms that travel in pairs.
- If atoms travel around in pairs, then we put a little ‘2’ at the bottom to show there are two atoms that are joined together.
- The elements that have atoms in pairs are:
- Oxygen, nitrogen, hydrogen, fluorine, chlorine, bromine, iodine.
Test yourself on Chemical Symbols
What is the chemical symbol for potassium?
What is the chemical symbol for gold?
Which of these elements has atoms that travel in pairs, needing a small 2 in its chemical formula?
A student wrote the chemical symbol for magnesium as 'MG'. What mistake have they made?