|Stockholm—Jöns Jacob Berzelius, Johan Gottlieb Gahn elements|
- Jöns Jacob Berzelius and Johan Gottlieb Gahn
- owned a chemical plant that produced sulfuric acid
- by the “lead chamber” process.
- Berzelius was professor in chemistry and pharmacy
- at the Karolinska Institute in Stockholm.
- Gahn was chemist for the Swedish Board of Mines.
- They found a red precipitate in the lead chambers
- that burned with a smell like horseradish.
- It was like tellurium, named for the Earth,
- so they named it selenium for the Moon.
Atomic number 34
- Selenium is sensitive to light;
- its electric resistance decreases
- when a light shines on it.
- Therefore, selenium is used
- in light meters, photocopiers,
- photocells, solar cells, and as a toner
- for developing black and white photographs.
Stuff with colors
- Powdered amorphous selenium
- is brick red.
- Rapidly melted into beads,
- it’s black.
- Its most stable and dense allotrope,
- forming hexagonal structures,
- is gray.
- Selenium dioxide polymer
- is yellow.
- A little selenium is good for you,
- even necessary,
- but too much is a horse
- of another color.