Chemistry: A Volatile History Chemistry: A Volatile History Chemistry: A Volatile History is a 2010 BBC documentary on the history of chemistry presented by Jim Al-Khalili. It was nominated for the 2010 British Academy Television Awards in the category Specialist Factual. Only in the last 200 years have we known what an element is – a substance that cannot be broken down further by chemical reaction. The Ancient Greeks, with no way of breaking open substances, could only base their ideas of the elements on what they could see: Earth, Fire, Water and Air. In the 16th century alchemists were busy trying to turn
Solidus (chemistry) Solidus (chemistry) In chemistry, materials science, and physics, the solidus is the locus of temperatures (a curve on a phase diagram) below which a given substance is completely solid (crystallized). The solidus is applied, among other materials, to metal alloys, ceramics, and natural rocks and minerals. The solidus quantifies the temperature at which melting of a substance "begins", but the substance is not necessarily melted "completely", i.e., the solidus is not necessarily a melting point. For this distinction, the solidus may be contrasted to the liquidus. The solidus is always less than or equal to the liquidus, but they need