In the early 20th century, the average American medicine cabinet was a would-be poisoner's treasure chest, with radioactive radium, thallium, and morphine in everyday products. The pace of industrial innovation increased, but the scientific knowledge to detect and prevent crimes committed with these materials lagged behind until 1918. New York City's first scientifically trained medical examiner, Charles Norris, and his chief toxicologist, Alexander Gettler, turned forensic chemistry into a formidable science and set the standards for the rest of the country.
After a short discussion of why chemical bonding occurs, this program explains how electrons are shared in covalent compounds. Viewers learn about the VSEPR theory, the two types of weak forces of attraction between molecules, dipole interactions and dispersion forces, and covalent network solids such as diamond, graphite, and fullerenes. With the assistance of animated graphics, the video provides a concise introduction to the key elements of covalent bonding.
Caught up in the race to discover the atom's internal parts--and learn how they fit together--is a young British physicist named Harry Moseley, who uses newly discovered X-rays to put the Periodic Table in a whole new light. And a young American chemist named Glenn Seaborg creates a new element--plutonium--that changes the world forever, unleashing a force of unimaginable destructive power: the atomic bomb.
Explores the phases of matter—solids, liquids, and gases—and how particles in a given phase interact with each other. Phase diagrams explain at what temperature and pressure a given substance will be in a solid, liquid, or gas phase. Practical problems, like how to safely store enough hydrogen gas to power an automobile, are solved by understanding the different behaviors of solids, liquids, and gases.