Movement of molecules from an area of higher concentration to one of lower concentration is called Diffusion
Answer: The correct option is C ( is very hard and burns cleanly).
Explanation:
COAL is a form of rock that is made up of mostly carbon amongst other elements which includes sulphur, nitrogen, hydrogen and oxygen. There are different types of coal which include:
--> anthracite ( 90% carbon)
--> bituminous coal ( 70-90% carbon)
--> lignite ( 60- 70% carbon) and
--> peat (60 % carbon).
Anthracite is the type of coal that contains the highest carbon content ( 90% carbon). This makes it very hard and is often a times referred to as HARD COAL. Anthracite is a higher quality coal for domestic and open fire heating. This is because it contains less impurities than other type of coal and thereby making it to BURN CLEANLY avoiding atmospheric pollution.
The answer to this question would be the second option or B (The moon's orbit is closer to Earth.) because there are multiple different high tides that are caused by either the moon being unusually close to the Earth or the moon is at it's Quarterly or New Moon phases.
Hope that this helped you! :D
I believe the answer is B!
