Boron



= ﻿ BORON! = **Atomic number** Boron is classified as a "Metalloid" element and is located in Groups 13, 14,15, 16 and 17 of the Periodic Table. An element classified as a Metalloid has properties of both metals and non-metals. Some are semi-conductors and can carry an electrical charge making them useful in calculators and computers. Name is made from a combination of Borax and Carbon! Elemental boron was not known until the early nineteenth century when Sir [|Humphrey Davy], [|Gay-Lussac] and Thenard prepared boron by reduction of boron trioxide with [|potassium] and by electrolysis of moistened boric acid. The purity of their products was about 50%. [] [] [] ||
 * 5 ||
 * **Atomic mass** || 10.81 g.mol -1 ||
 * **Electronegativity according to Pauling** || 2.0 ||
 * **Density** || 2.3 g.cm-3 at 20°C ||
 * **Melting point** || 2076 °C ||
 * **Boiling point** || 3927 °C ||
 * **Vanderwaals radius** || 0.098 nm ||
 * **Ionic radius** || 0.027 nm ||
 * **Isotopes** || 2 ||
 * **Electronic shell** || [ He ] 2s22p1 ||
 * **Energy of first ionisation** || 800.5 kJ.mol -1 ||
 * **Energy of second ionisation** || 2426.5 kJ.mol -1 ||
 * **Energy of third ionisation** || 3658.7 kJ.mol -1 ||
 * **Discovered by** || Sir Humphry Davy and J.L Gay-Lussac in 1808 ||