atomic no. 27, atomic wt. 58.94, metal, row 5, col. 7B, val. 2-3, orbits 2-8-15-2

{Merck Index - © 1952 by Merck & Co., Inc.}

Cobalt. CO; at. wt. 58.94; at. no. 27; valence 2-3.

Discovered in 1735 by Brandt.

Gray, hard, magnetic, ductile, somewhat

malleable metal. Crystallizes in hexagonal or cubic form. Stable in air or toward water at ordinary temp. d. 8.9. m. 1480°. b. 2900°. Brinell hardness = 125. Readily soluble in dil. HNO3; very slowly attacked by HCI or cold H2SO4.

The hydrated salts of cobalt are red, and the soluble salts form red solns. which become blue on adding concentr. HCl.

Use: For alloys; manuf. cobalt salts. Commercially available.

Toxicity: Inhalation of dust may cause pulmonary symptoms. Powder may cause dermatitis.

Max. allowable concn. reported to be 0.5 mg./cu. m. of air. Ingestion of soluble salts produces nausea and vomiting by local irritation.

{Mineral Deficiencies in Plants}

Link to Chemical

Hydroponic Reference Center Project Page

Color Pictures of Mineral Defeciencies in Plants

Site Link List - Element List - Hydroponic Salts

Tortoise Shell Life Science Puzzle Box – Front Page

View this page Full Frame