An article states that the fission of 2.0 g of uranium−235 releases 6.8 × 108 kcal, the same amount of energy as burning two tons (4,000 lb) of coal. if this report is accurate, how much energy is released when 1.0 g of coal is burned?

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer. the ice dissolves oxygen from the air, forming a denser crystalline matrix. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds.