13
Room of the Elements · No. 13
Aluminium (Al): what kind of element is it?
日本語
In short
Aluminium is element number 13, a metal with the symbol Al. Japan’s one-yen coin is made of pure aluminium, and each coin weighs exactly 1 g.
Atomic number 1326.98
AlAluminiumアルミニウム (aruminiumu)- Symbol
- Al
- Atomic weight
- 26.98
- Place in the table
- Period 3 · Group 13
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
The one-yen coin
According to the Japan Mint, the one-yen coin is made of pure aluminium. It weighs 1 g, is 20 mm across, and has been issued since 1955.
Of the six coins Japan makes today, only the one-yen coin is aluminium. The other five all contain copper.
Named after alum
The name comes from alumen, Latin for alum, a substance that contains aluminium. Aluminium was discovered in 1825.
The Chemical Society of Japan writes the English name as “aluminium.” It is also spelled “aluminum” in English.
Think about it
- Q1Does a one-yen coin stick to a magnet? Guess first, then try it.
- Q2How could it be useful that a one-yen coin weighs exactly 1 g?
- Q3What things around you are made of aluminium?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — One hundred one-yen coins weigh exactly 100 g, so you can use them to check whether a kitchen scale is accurate.