Why the color of coal is black?

Answer 1

Remember that coal is made from plants that were buried deep millions of years ago. Underground the plant stuff was squeezed by lots of soil and rock and became very hot because it is very hot underground. There is no air in deep rock, so the plant stuff could not burn, but it baked like bread till it turned black in two ways.

The first way was that some of the plant stuff changed into chemicals like tar that are black in colour.

The second way was that some of the plant stuff charred like a stick in the fire, leaving only black carbon. Some kinds of coal have more tar and other kinds have more carbon. The hotter it became and the deeper it was buried and the longer it stayed underground, the darker and harder it became.

Carbon and tars are black because light that we can see cannot pass through, and light that hits the coal mostly does not get reflected. Instead the coal takes up the light and grows warmer. So we see very little light from the coal, and this makes it look black.

Answer 2

Coal appears black in color due to its high carbon content. The carbon present in coal absorbs most of the visible light that strikes it, resulting in the black color we see. This carbon content is also what gives coal its properties that make it useful for fuel and energy production.