Week 3:   Favorite website was definitely the Visionlearning site.... Clear definitions of concepts, and simple useful graphics to illustrate those definitions.  Will use that one again....

Transition Metal :  Cobalt, Co

Protons: 27, Neutrons: 32, atomic mass: 58. Four energy levels.

Has a hexagonal crystal structure and a silver color.

Some character sold me a pair of high end haircutting shears once claiming that they were extra hard as they had cobalt in them.  I suppose it might be possible that they were electroplated with a corrosion and wear-resistant alloy of cobalt.....? Which would be good, since you lose a bit of your shears every time you get them sharpened. 

Pure cobalt is not found in nature, but compounds of it occur in many forms... by-products of nickel and copper mining (ores, used to make alloys...) Its compounds are used in the production of inks, paints, varnishes, magnets, ceramics, special glasses....

One source says it is obtained from arsenic, oxygen, sulfur, and cobaltine. Apparently mammals require small amounts of it and it is the basis of Vitamin B12 (says Wikipedia).

Cobalt was discovered by George Brandt in 1737 and named after the German Kobalt (Kobold), which means goblin, or evil spirit---probably since it poisoned miners when they first tried to smelt it (gave off arsenic).....