Promethium is what is known as a "lanthanide" or "rare-earth metal." This metal is one of 15 elements that occupy the lower portion of the periodic table and carry the atomic numbers 57 through 71.
The conversion of atmospheric nitrogen, N 2, to more valuable compounds is a challenge that has confronted chemists for over a century. Molecules containing nitrogen atoms are the cornerstone of ...
Apoptosis, the dominant form of programmed cell death, refers to the shedding of the leaves from trees in Greek. The distinct morphological changes of cells undergoing apoptosis are sequentially ...