Mr. Obama rarely plays with other politicians - though he has played 7 times with Vice President Biden. In a fence-mending gesture, Mr. Obama invited then-House Speaker John Boehner to play on one occasion in June 2011 along with Gov. John Kasich, both Ohio Republicans.
Here are some ways to classify coal (by grouping it with similar types of rocks): Because slag formed from lava-like melted rock, it's sort of like an igneous rock -- but because humans made the melt, it's not a true igneous rock. So, we made up a new classification for slag: We call it a pseudo-igneous rock (pronounced SUE-doe ig-NEE-us).
Confidence votes 3.2K. When you burn coal to generate electricity (or even to heat your home) the gas going up the chimney contains carbon dioxide, water vapor, nitrogen, nitrous oxides, sulfur oxides, fly ash and mercury.There is also solid waste ash that must be removed afterwards, though some of this can be used in building.ome coal contains sulfur or sulfur compounds. These can be released by burning to produce sulfur dioxide, which reacts with water in the atmosphere to produce sulfurous and sulfuric acids, which are significant components of acid rain.