How is coal extracted from mountaintop removal mines?
a.
dynamite is used to create underground tunnels where miners go to extract the coal.
b.
dynamite is used to break apart rocks and then draglines are used to remove the broken rock and reach the coal.
c.
coal in mountaintops is extracted by digging strips in the landscape to reach the coal.
d.
placer deposits in mountain river bottoms are removed by sifting through sediment.

How have the greenhouse gasses increased from the year 2000 to 2018

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .

Who discovered a pattern to the elements in 1869?