(Encyclopedia) cobalt, metallic chemical element; symbol Co; at. no. 27; at. wt. 58.9332; m.p. 1,495℃; b.p. about 2,870℃; sp. gr. 8.9 at 20℃; valence +2 or +3. Cobalt is a silver-white, lustrous,…
(Encyclopedia) moscoviummoscoviummŏskōˈvēəm [key], artificially produced radioactive chemical element; symbol Mc; at. no. 115; mass number of most stable isotope 288; m.p., b.p., sp. gr., and valence…
Dinosaur communities were separated by both time and geography. The “age of dinosaurs” (the Mesozoic Era) included three consecutive geologic time periods (the Triassic, Jurassic, and Cretaceous…
—By Karen Barss The story of human evolution began in Africa about six million years ago and it describes the very long process that our ancestors went through to ultimately become modern humans.…
WHAT IS THE SUN MADE OF? WHAT IS THE SURFACE OF THE SUN LIKE? SOLAR ECLIPSESFIND OUT MOREAt the center of the Solar System is the Sun, a vast globe of glowing gas that pours energy into space as…
