2. Scientists have theorized that an increased
concentration of carbon dioxide will cause an
increase in worldwide atmospheric temperature,
This theory is based on the fact that carbon
dioxide is a
A good absorber of infrared radiation
B.
poor absorber of infrared radiation
C. good reflector of ultraviolet radiation
D
poor reflector of ultraviolet radiation

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.