Chromium is element number 24, a metal with the symbol Cr. Its name comes from the Greek word for “color.”
Atomic number 2452.00
CrChromiumクロム (kuromu)
Symbol
Cr
Atomic weight
52.00
Place in the table
Period 4 · Group 6
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
Named for color
The symbol Cr comes from the Greek chroma, “color,” because chromium’s compounds come in a great many colors. It was discovered in 1797.
Chromium and the body
Chromium is one of the trace minerals for which Japan’s Ministry of Health sets dietary reference values. The chromium in food is in a form called trivalent chromium.
Chromium is in the fourth row of Group 6. Its neighbor vanadium is also named for the beautiful colors of its compounds.
Think about it
Q1Why do you think the same element can make compounds of different colors?
Q2Do you know any other elements named for color?
Q3Why might the body need some elements in only very small amounts?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Elements named for colors include chlorine (yellow-green), chromium (color), rhodium (rose) and iridium (rainbow).