Explains how energy used for various activities is released by burning wood, coal, oil, gas, and other fuels, as well as by the wind, moving water, nuclear fission, and the sun
Discusses the qualities of magnets, which attract certain metals and have been used as compasses and as components of many modern inventions, including the telephone, television, and electric motor
Describes the difficulties encountered by settlers who traveled westward in covered wagons or prairie schooners along the Oregon Trail during the 1830's and 1840's.
Discusses the qualities of magnets, which attract certain metals and have been used as compasses and as components of many modern inventions, including the telephone, television, and electric motor
Explains how the growth of industry in modern times has brought about the pollution of air, water, and land, as well as the depletion of natural resources, and emphasizes the importance of conservation