Coal formation begins with the decay of plants and animals in the absence of oxygen. Bacteria release oxygen and hydrogen and concentrate carbon. Impurities are removed over time, and the weight of sediment compresses the matter, leaving a material with a very high carbon concentration.
Most coal was formed about 300 million years ago. During this time, Earth was primarily covered by swamps. Dying plants and trees sank into these swamps. As the climate changed and swamps dried up, rivers and streams deposited sediment on top of these remains, creating large coal beds. Coal production continues in swampy areas of Earth, with a completion date millions of years in the future.Learn More
The correct name for the compound Sn3(PO4)2 is anhydrous stannous phosphate. This name is most often used in industrial contexts. Stannous phosphate is also known as tin phosphate.Full Answer >
The sequence of the cell cycle is G1, S, G2, mitosis and cytokinesis. G1 and G2 are "gap" phases during which the cell grows and prepares for other phases. The S phase is the stage when DNA is copied. Mitosis divides the copies of DNA, and cytokinesis creates two new cells.Full Answer >
Anaerobic respiration refers to the enzymatic breakdown of sugar for energy in the absence of oxygen. Most cells in the human body can perform anaerobic respiration, at least for short periods of time. One molecule of glucose metabolized anaerobically to pyruvate yields two molecules of adenosine triphosphate (ATP); this is a low yield compared to aerobic respiration, in which 36 ATP molecules are generated for each glucose molecule metabolized.Full Answer >
Coal is nonrenewable because it comes from fossil fuels, and fossil fuels take millions of years to form. Fossil fuels are the product of decomposed materials and organisms that have been heated and pressurized for millions of years.Full Answer >