Pour 4 mL of hydrogen peroxide into a clean test tube and obtain a small amount of manganese dioxide. (Manganese dioxide is a catalyst, something used to increase the speed of a reaction but is not used up or
produced in the reaction.)

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.

answer///carbon;