Answer:
F Anthracite (the hardest coal)
Explanation:
Coal is a sedimentary rock that is formed from plant materials. These plant materials must have been trapped and compacted in an environment where they are not able decay. Such an environment is a swamp.
The first grade of coal that forms initially in such an environment is called PEAT. Peat is soft coal that still contains some plant materials. It has a high moisture content and the amount of carbon is still quite low.
With increasing pressure and compaction, PEAT grades into LIGNITE which has more carbon atoms in it. Lignite is more combustible although it is quite soft too. Lignite grades into SUB-BITUMINOUS coal and then BITUMIOUS coal.
The highest grade of coal is ANTHRACITE which is a hard coal. It has very little moisture content and rich carbon percentage in it. Anthracite yields more energy compared to other forms of coal. Anthracite is basically coal that forms at the greastest pressure. Beyond this pressure, a metamorphic transformation occurs and the coals changes to graphite.
Based on increasing pressure:
PEAT< LIGNITE< BITUMINOUS COAL < ANTHRACITE
The largest supply of water on Earth is actually in the form of d. glaciers and icecaps - and quite in fact most of the water in glaciers and icecaps is collected in one space- in Antarctica!
Therere is a lot of water in the oceans, but it's not freshwater because it's salty.
Answer:
6
(Ignore this its for 20 characters)
Answer:
<h3>Migration can be defined as “a process of moving, either across an interna- tional border, or within a State. ... The phenomenon of migration has been indispensable to human histories, cultures, and civilizations</h3>
Answer:
North America will be wetter in winter, but drier in summer.
Explanation:
What do computer models predict about how precipitation patterns will change in North America for the period 2090-2099, relative to the years 1980-1999? North America will be wetter in winter, but drier in summer.
