Résultats Éditeur "Tantor Audio" dans Chimie

Each day we are exposed to a myriad of natural and human-made chemicals in our food, drinking water, air, soil, at home or at the workplace-pesticide residues, food additives, drugs, household products-but how can we gauge the human health risk posed by these chemicals? Should we believe the somber headlines that depict a serious threat for humans and the environment, or should we follow the reassuring voices of others who claim that the angst is totally unfounded?

The charges of the proton and electron are opposite and equal, even though the proton is bigger. But why are they equal? This is one of the deepest unresolved puzzles of physics. Frank Close takes us on a journey into the quantum subatomic world of particles. He describes the strong and weak forces that operate alongside electromagnetism, the color and flavor charges, as well as the parallels between them, giving hints of a deeper unity.