The disappearance of the purple colour of KMnO4 in it's reaction with alkene is known as​

Reduction. KMnO4 is an oxidizing agent(oxidizes substances) Therefore it is reduced. The MnO4-(purple colour) from the KMnO4 is reduced to Mn2+(pale pink/ colourless).

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.

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa