Zinc iodide is a iodide of zinc. It is used in x-rays and electron microscopy. Zinc is a metallic element with the atomic number 30. It is found in nature most often as the mineral sphalerite. Though excess zinc in harmful, in smaller amounts it is an essential element for life, as it is a cofactor for over 300 enzymes and is found in just as many transcription factors. (L48, L49, L69)
