Quantcast

Chemistry Reference Libraries

Page 11 of about 102 Articles
Zircon Dust
2005-05-25 10:17:59

Zircon is a mineral belonging to the group of nesosilicates. Its chemical formula is ZrSiO4. Hafnium is almost always present ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal class. The natural color of zircon varies between colorless, yellow-golden, red, brown or green. Specimens that show gem quality are a popular substitute for diamond (but note that cubic zirconia...

Earths Atmosphere
2004-10-19 04:45:44

Earth's Atmosphere -- Earth's atmosphere consists of nitrogen (78.1%) and oxygen (20.9%), with small amounts of argon (0.9%), carbon dioxide (variable, but around 0.035%), water vapor, and other gases. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night. 75% of the atmosphere exists within 11km of the...

Word of the Day
ecotone
  • A transitional zone between two communities containing the characteristic species of each.
The word 'ecotone' comes 'eco-' plus a Greek root meaning 'tension'.