Zinc Dichromate Trihydrate

See more Chromium products. Chromium (atomic symbol: Cr, atomic number: 24) is a Block D, Group 6, Period 4 element with an atomic weight of 51.9961. The number of electrons in each of Chromium's shells is 2, 8, 13, 1 and its electron configuration is [Ar] 3d⁵ 4s¹. Louis Nicolas Vauquelin first discovered chromium in 1797 and first isolated it the following year. The chromium atom has a radius of 128 pm and a Van der Waals radius of 189 pm. In its elemental form, chromium has a lustrous steel-gray appearance. Chromium is the hardest metallic element in the periodic table and the only element that exhibits antiferromagnetic ordering at room temperature, above which it transforms into a paramagnetic solid. The most common source of chromium is chromite ore (FeCr₂O₄). Due to its various colorful compounds, Chromium was named after the Greek word 'chroma.' meaning color.

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.