http://www.anatomyzone.com. 3D anatomy tutorial providing a basic introduction to respiratory anatomy using the Zygote Body Browser (http://www.zygotebody.com). This is the second part of the tutorial and covers the bronchial tree and lungs.Join the Facebook page for updates: http://www.facebook.com/anatomyzone.his is the second part of the tutorial and covers the bronchial tree and lungs. Join the Facebook page for updates: http://www.facebook.com/anatomyzone.
The average atomic mass of carbon is 12.011. This is a weighted average based on three forms (isotopes) of carbon with different natural abundances. Carbon 12 has an atomic mass of 12.00 (carbon 12 is a special case because its mass is <i>defined</i> to be exactly 12 atomic mass units) and a natural abundance of 0.9893.
This makes the atomic weight of natural carbon 12.010. Carbon is the 19th most abundant element in the earth's crust, at 0.027%. It is found as carbon dioxide, carbonate rocks, and living matter. It occurs in elemental form in small amounts, as graphite and diamond. The properties of these forms of carbon, which are very important, are discussed in separate sections.