Three atoms of this element form a compound analogous to benzene by alternating with three atoms of nitrogen.
The sodium salt of this element's hydride is used as a soft reducing agent in organic chemistry, and most laboratory glassware is heat-resistant because it is fifteen percent this element's oxide. This element is used to dope germanium to enhance p-type conductivity. It forms compounds with hydrogen that are given prefixes like nido- and arachno-. Three atoms of this element form a compound analogous to benzene by alternating with three atoms of nitrogen. For 10 points, name this element found in ulexite (OO-lex-ite) and borax with atomic number five.
The sodium salt of this element's hydride is used as a soft reducing agent in organic chemistry, and most laboratory glassware is heat-resistant because it is fifteen percent this element's oxide.
{boron} [or {B}]