ODWS icon

The Open Door Web Site
HOMEPAGE BIOLOGY PHYSICS ELECTRONICS HISTORY HISTORY OF SCI & TECH MATH STUDIES LEARNING FRENCH STUDY GUIDE  PHOTO GALLERY
CHEMISTRY HOMEPAGE TOPIC CHAPTERS PHYSICAL SCIENCE LABORATORY WORK 

 

 

 

Navigation

Next (in period)
Previous (in period)
Visual Chemistry Homepage : The Periodic Table

 

Tutorials

Atomic Structure
Electrovalent Bonding
Covalent Bonding
Water
Transition Metals
Metal or Non-metal?
Noble Gases

 

General

Element Identification Timeline

VISUAL CHEMISTRY

Custom Search

Chromium

What the name means: Chromium comes from the Greek word khroma (or chroma) meaning colour.

Chromium

Chromium atom

Chromium atom

 

 

Chromium III ion

Chromium IV ion

Chromium III ion

Chromium IV ion

Who identified chromium?: In 1761 a German geologist called Johann Gottlob Lehmann, while working in gold mines in the Ural Mountains of Siberia, made observations on a mineral that he believed was a form of red lead. The mineral became known as Siberian red lead. Lehmann's work was short lived (he died in a chemical explosion in 1767) but before the accident he did communicate his observations to Georges-Louis Leclerc, Comte de Buffon, which is why we know about Lehmann's part in the story.

The mineral that Lehmann studied was not, in fact, red lead, Siberian or otherwise, but an ore called crocoite, that contains a compound made from lead, chromium and oxygen. In 1770 a German biologist, Peter Simon Pallas, while on an expedition to the Ural Mountains, discovered the value of crocoite ore in providing pigments for paints. The bright yellow colour it gave to paint became extremely fashionable.

In 1797, Nicolas-Louis Vauquelin, while working for the Comte de Fourcroy, was successful in isolating the new element from crocoite. At the suggestion of the Comte de Fourcroy and the mineralologist René Just Haüy, he called the new element chromium on account of the many different colours it produced when it reacted with various chemicals.

 

Properties

CRPROPS

STP = standard temperature and pressure.
Usually considered as room temperature and pressure.

 

About chromium: Chromium is a hard, silvery looking metal. It is mostly mined as chromite, a compound of chromium and oxygen with iron and magnesium. Free chromium is rare in nature but it can be found in certain mines in Russia, particularly where there are diamonds.

Chromium metal is mostly used mixed with other metals to form alloys. Since it is a hard metal it can help strengthen other metals. It is also necessary in trace amounts in the human body where, as the Cr3+ ion, it is essential for insulin to function correctly in regulating the body's sugar levels.

 

The Open Door Web Site is non-profit making. Your donations help towards the cost of maintaining this free service on-line.

Donate to the Open Door Web Site using PayPal

SITE MAP
WHAT'S NEW?
ABOUT

PRIVACY

COPYRIGHT

SPONSORSHIP

DONATIONS

ADVERTISING

© The Open Door Team 2017
Any questions or problems regarding this site should be addressed to the webmaster

© Shirley Burchill 2017

Hosted By
Web Hosting by HostCentric


SiteLock