Why can graphite be used as pencil lead? Firstly, it is black; secondly, it has a soft texture and is one of the softest minerals. Graphite is one of the softest minerals in carbon. Its uses include the manufacture of pencil leads and lubricants. Swipe it lightly on the paper, leaving a trace. If observed under a magnifying glass, the pencil trace is composed of tiny graphite particles. The hardness of the ore is an important indicator to identify the type of ore. Scientists divide the hardness of ore into ten grades: graphite and talc are the softest and can be imprinted with a nail. Their hardness is 1; the hardness of steel is 4; the hardness of granite is 6-7; the hardest The hardness of the substance diamond is 10.
Graphite and diamond are two brothers in the carbon family of chemical elements, and both consist of the same kind of carbon atoms. However, graphite is black and soft, but diamond is crystal clear and extremely hard. The two brothers are called “soft brother” and “hard brother”, and their temperaments are so different. What is the reason for this? It turns out that in graphite, the carbon atoms are arranged in layers, and the carbon atoms hold hands in the same layer and are closely connected; the bond between the layers is loose, like a spiral playing card, with a light push , The cards slid between the cards, scattered on the paper, leaving dots of ink marks.