Which of the following might be an indicator of global warming?
a. average increase in the temperatures near earth's surface
b. a decrease in greenhouse gases
c. average decrease in the temperatures near earth's surface
d. a decrease in carbon dioxide emissions

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

Fossil fuels are organic compounds that are made from

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.