'Turn-on' fluorescent chemosensors based on naphthaldehyde-2-pyridinehydrazone compounds for the detection of zinc ion in water at neutral pH.

See more Zinc products. Zinc (atomic symbol: Zn, atomic number: 30) is a Block D, Group 12, Period 4 element with an atomic weight of 65.38. The number of electrons in each of zinc's shells is 2, 8, 18, 2, and its electron configuration is [Ar] 3d¹⁰ 4s². The zinc atom has a radius of 134 pm and a Van der Waals radius of 210 pm. Zinc was discovered by Indian metallurgists prior to 1000 BC and first recognized as a unique element by Rasaratna Samuccaya in 800. Zinc was first isolated by Andreas Marggraf in 1746. In its elemental form, zinc has a silver-gray appearance. It is brittle at ordinary temperatures but malleable at 100 °C to 150 °C. It is a fair conductor of electricity, and burns in air at high red producing white clouds of the oxide. Zinc is mined from sulfidic ore deposits. It is the 24th most abundant element in the earth's crust and the fourth most common metal in use (after iron, aluminum, and copper). The name zinc originates from the German word "zin," meaning tin.