Key Concepts. Photochemical smog is a type of air pollution produced when sunlight acts upon motor vehicle exhaust gases to form harmful substances such as ozone (O. Photochemical smog formation requires the following conditions: 1  a still, sunny day. 2  temperature inversion (pollutants accumulate in the lower inversion layer).
Chebanse, Illinois. Chebanse is a village in Iroquois and Kankakee counties in the U.S. state of Illinois. The population was 1,148 at the 2000 census, and 1,088 in 2009. The Kankakee County portion of Chebanse is included in the Kankakee-Bradley, Illinois Metropolitan Statistical Area. Contents.
Elgin (/ËÉldÊáµ»n/ EL-jin) is a city in Cook and Kane counties in the northern part of the U.S. state of Illinois. Located roughly 35 mi (56 km) northwest of Chicago, it lies along the Fox River. As of 2013, the city had a total population of 110,145, making it the eighth-largest city in Illinois.