MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY
Digital weighing scales. Pieces of graphite, an allotrope of carbon, in a petri dish being weighed on digital scales. The liquid crystal display is showing a reading of twelve grammes. Since carbon's relative atomic mass is approximately twelve, this means there is about one mole unit measurement of carbon here. Graphite is a soft and slippery substance to touch, and has a melting point in excess of 3500 degrees Celsius. It has a wide variety of uses including the "lead" in pencils, as a lubricant in industry, and as a flame retardant. In 1961, the International Union of Pure and Applied Chemistry adopted the isotope carbon-12 as a basis for atomic weights.
Model release not required. Property release not required.