Comparative effect of a stannous fluoride toothpaste and a sodium fluoride toothpaste on a multispecies biofilm.

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 Tin products. Tin (atomic symbol: Sn, atomic number: 50) is a Block P, Group 14, Period 5 element with an atomic weight of 118.710. The number of electrons in each of tin's shells is 2, 8, 18, 18, 4 and its electron configuration is [Kr] 4d¹⁰ 5s² 5p². The tin atom has a radius of 140.5 pm and a Van der Waals radius of 217 pm.In its elemental form, tin has a silvery-gray metallic appearance. It is malleable, ductile and highly crystalline. Tin has nine stable isotopes and 18 unstable isotopes. Under 3.72 degrees Kelvin, Tin becomes a superconductor. Applications for tin include soldering, plating, and such alloys as pewter. The first uses of tin can be dated to the Bronze Age around 3000 BC in which tin and copper were combined to make the alloy bronze. The origin of the word tin comes from the Latin word Stannum which translates to the Anglo-Saxon word tin. For more information on tin, including properties, safety data, research, and American Elements' catalog of tin products, visit the Tin element page.

Fluorine is a Block P, Group 17, Period 2 element. Its electron configuration is [He]2s²2p⁵. The fluorine atom has a covalent radius of 64 pm and its Van der Waals radius is 135 pm. In its elemental form, CAS 7782-41-4, fluorine gas has a pale yellow appearance. Fluorine was discovered by André-Marie Ampère in 1810. It was first isolated by Henri Moissan in 1886.