Hoovervilles and the economy. As the economic crash of the 1930s dragged on, more and more people were ruined. Delinquent taxes, drastically rising unemployment and mortgage foreclosures were heavy burdens to overcome. Those factors forced ordinary people to either move into Hoovervilles or become transients.
Carbon is the sixth most common element in the universe and the fourth most common element in the solar system. It is the second most common element in the human body after oxygen. About 18 percent of a person's body weight is due to carbon. The black color of smoke is caused by unburned specks of carbon.
Carbon also forms double and triple bonds with several other elements that can exhibit a covalence of two or three. The carbon-oxygen (or carbonyl) double bond appears in carbon dioxide and many important organic compounds such as methanal (formaldehyde) and ethanoic acid (acetic acid). Similarly, a carbon-nitrogen triple bond appears in methanenitrile (hydrogen cyanide) and eth-anenitrile (acetonitrile).