Aqueous solutions of a compound of this element, potassium, and sulfate are purple but turn green when heated above 50 degrees Celsius; aqueous solutions of many other compounds of this element (-5[1])instead shift from purple to green over time. A compound made of this element bonded to two oxygens and two chlorines is a bromine-like volatile (-5[1])red-brown liquid. (-5[1])The first known quadruple bond was between two atoms of this element in an acetate of this element. The red color of ruby is caused by ions (10[1])of this element (10[1])replacing some aluminum atoms in the crystal lattice of corundum. Yellow and orange oxyanions of this element are powerful oxidizers, as is (10[1])its red trioxide; all of those are examples of this element's carcinogenic (10[1])hexavalent form. For 10 points, (10[1])name this transition metal that provides the corrosion resistance (-5[1])of stainless steel. (10[1])■END■ (10[1]0[2])