RRB NTPC Mains or Stage 2 Model Paper 1 with solutions

(3) Graphite is a good conductor of heat and electricity. This is because of the presence of delocalised electrons, as each carbon atom forms only three covalent bonds with three other carbon atoms. These electrons are free to move through the structure of the graphite.Graphite is used extensively for making core of electro chemical cells and Lead pencil.