Methylthymol Blue

See more Sodium products. Sodium (atomic symbol: Na, atomic number: 11) is a Block D, Group 5, Period 4 element with an atomic weight of 22.989769. The number of electrons in each of Sodium's shells is [2, 8, 1] and its electron configuration is [Ne] 3s¹. The sodium atom has a radius of 185.8 pm and a Van der Waals radius of 227 pm. Sodium was discovered and first isolated by Sir Humphrey Davy in 1807. In its elemental form, sodium has a silvery-white metallic appearance. It is the sixth most abundant element, making up 2.6 % of the earth's crust. Sodium does not occur in nature as a free element and must be extracted from its compounds (e.g., feldspars, sodalite, and rock salt). The name Sodium is thought to come from the Arabic word suda, meaning "headache" (due to sodium carbonate's headache-alleviating properties), and its elemental symbol Na comes from natrium, its Latin name.

See more Sulfur products. Sulfur (or Sulphur) (atomic symbol: S, atomic number: 16) is a Block P, Group 16, Period 3 element with an atomic radius of 32.066. The number of electrons in each of Sulfur's shells is 2, 8, 6 and its electron configuration is [Ne] 3s² 3p⁴. In its elemental form, sulfur has a light yellow appearance. The sulfur atom has a covalent radius of 105 pm and a Van der Waals radius of 180 pm. In nature, sulfur can be found in hot springs, meteorites, volcanoes, and as galena, gypsum, and epsom salts. Sulfur has been known since ancient times but was not accepted as an element until 1777, when Antoine Lavoisier helped to convince the scientific community that it was an element and not a compound.