Electricity (Encyclopedia of Science)
Electricity is a form of energy caused by the presence of electrical charges in matter. All matter consists of atoms, and atoms themselves contain charged particles. Each proton in an atomic nucleus carries one unit of positive electric charge, and each electron circling a nucleus carries one unit of negative electric charge. Electrical phenomena occur when electrons escape from atoms. The loss of one or more electrons (negative charges) from an atom leaves behind a positively charged fragment known as a positive ion. An electric current is produced when a mass of electrons released from atoms begins to flow.
Static and current electricity
Electrical phenomena can be classified in one of two general categories: static electricity or current electricity. The term static electricity refers to the behavior of electrical charges at rest. Suppose you hang two ping-pong balls from silk threads so that they are about 2 inches (5 centimeters) apart. Then imagine that each ball is rubbed with a piece of wool. The two balls become electrically charged with the same sign. Because like charges repel each other, the two balls will swing away from each other because of the static charge on each one.
Current electricity refers to the behavior of electrical charges in motion. In order for charged particles to flow, some pathway must be provided...
(The entire section is 1633 words.)
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Electricity (Science Experiments)
How electricity flows through liquids
Electrolytes: Do some solutions conduct electricity better than others?
Design Your Own Experiment
We know that electricity will flow through certain objects and not others. We are told that it is dangerous to plug in an ungrounded electrical device while standing in water because the electricity may flow through our bodies and the water to the ground, giving us a shock. But how, exactly, does water conduct electricity? Do all liquids conduct electricity equally well? And how have we made this property useful in our everyday lives?
Most of the electricity we use every day is conducted from its source through metal wires to the appliances we use. Most metals, such as copper, conduct electricity well because they possess a great number of free electrons. An is an extremely small particle with a single electrical charge that orbits the nucleus of an atom. Materials with few or no free electrons do not conduct electricity and are called
(The entire section is 3460 words.)
Electricity (West's Encyclopedia of American Law)
Electricity has been known since ancient times, but scientists could not make use of it safely until the eighteenth century. Thomas Edison's invention of the electric lightbulb in 1879 sparked the demand for electric power that continues to this day, ultimately resulting in the need for legislative and regulatory controls on the electric-power-generating industry.
By the end of the nineteenth century, the United States had completed its transition from using wood as a major energy source to using coal, and the next transition from coal to oil and natural gas was just beginning. By the early twentieth century, both homes and businesses increased their demand for electric power, and electric utilities obtained long-term franchises from municipalities.
In 1920, the Federal Power Act (FPA), 16 U.S.C.A. §§ 791a28c, was passed in response to increased competition between electric utilities and a lack of consistent service to rural areas. The Federal Power Act gave the Federal Power Commission the authority to license hydroelectric plants. Later, President FRANKLIN D. ROOSEVELT encouraged Congress to create part II of the act, which gave the Federal Power Commission the power to regulate the transmission of electric energy (16 U.S.C.A. §§ 82424m). This legislation was necessary to guard against potential abuses of the utility companies'...
(The entire section is 1950 words.)