Chloroplatinic Acid Hydrate

See more Platinum products. Platinum (atomic symbol: Pt, atomic number: 78) is a Block D, Group 10, Period 6 element with an atomic weight of 195.084. The number of electrons in each of platinum's shells is [2, 8, 18, 32, 17, 1] and its electron configuration is [Xe] 4f¹⁴ 5d⁹ 6s¹. The platinum atom has a radius of 139 pm and a Van der Waals radius of 175 pm. Platinum was discovered and first isolated by Antonio de Ulloa in 1735. It is one of the rarest elements in the earth's crust, occurring at a concentration of only 0.005 ppm. Platinum is found uncombined as a free element and alloyed with iridium as platiniridium. In its elemental form, platinum has a grayish white appearance. It is highly resistant to corrosion: the metal does not oxidize in air at any temperature. It is generally non-reactive, even at high temperatures. The origin of the name "platinum" comes from the Spanish word platina, meaning silver.

Chlorine is a Block P, Group 17, Period 3 element. Its electron configuration is [Ne]3s²3p⁵. The chlorine atom has a covalent radius of 102±4 pm and its Van der Waals radius is 175 pm. In its elemental form, chlorine is a yellow-green gas. Chlorine is the second lightest halogen after fluorine. It has the third highest electronegativity and the highest electron affinity of all elements, making it a strong oxidizing agent. It is rarely found by itself in nature. Chlorine was discovered and first isolated by Carl Wilhelm Scheele in 1774. It was first recognized as an element by Humphry Davy in 1808.