A compound consisting of 6 atoms of this element bound to lanthanum crystallizes to form a low temperature superconductor with a low work function. 40 atoms of this element can form spheres analogously to 60 atom carbon buckyballs. (10[1])An extremely sterically hindered D2h molecule features two atoms of this element that are bridged by two hydrogens. Adding this element to pinacol or catechol (10[1])leads to the formation of a 5-membered ring in which this element is bound to two oxygens and a hydrogen. Wade’s rules are used to predict the structure (10[1])of (10[1])compounds containing this element, which forms 3-center 2-electron bonds (10[1])with hydrogen. This element forms 3 bonds without possessing a lone pair, thus violating the octet rule. For 10 points, name this element with atomic number 5. (10[1])■END■ (10[2]0[1])