一级亚洲做人爱c视频三分钟Chemistry is the science of molecules. Scientific, medical, and technological phenomena ultimately are understood in terms of molecular structure and interactions. Understanding of chemistry is essential to effective work in all sciences, and some knowledge of chemistry is useful in such fields as law, government, business, and art.  Many aspects of our high-technology society can be understood better from the viewpoint of chemistry.






The Periodic Tabloid

From The Connection