Diamond electrodes doped with this element may be used in organic electro-synthesis due to their large electrochemical window. Hydroxylation reactions often use a disiamyl-substituted compound of this element. (15[1])A bulky compound (15[1])of this element (15[2])and a phosphine form the classic frustrated Lewis pair. A base attacks (15[1])this element before transmetallating an aryl group onto palladium in the (*) Suzuki coupling. (10[2])This element (10[4])adds (-5[2])across a double bond, (-5[1])followed by oxidation with a peroxide, (10[1])in an anti-Markovnikov (10[5]-5[3])addition (10[2])of water across (10[2])a double bond. (10[3]-5[3])This element’s trihydride (10[1])dimerizes (10[1])into a (10[1])compound with two three-center, two-electron bonds, (10[1])since this element typically only forms three covalent (10[2])bonds (10[2])in violation of the octet rule. (10[1])For 10 (10[1])points, name this trivalent (10[1])element whose atomic number is 5. (10[4])■END■ (10[8]0[2])