Which sentence indicates that curium is a not a mineral? curium is a chemical element. it is a hard metal that looks like silver in light and glows red in the dark. it was first identified by american scientists working with nuclear energy during world war ii. the scientists, who included glenn seaborg, ralph james, and albert ghiorso, named the element after marie and pierre curie, nobel prize-winning scientists. they found that this human-made element is created when plutonium is bombarded with alpha-particles using a cyclotron. curium is a highly radioactive substance. it is extremely hazardous to human health. on entering the human body, it can hamper the production of red blood corpuscles and cause cancer. however, scientists continue to produce the element for its usefulness in scientific research. for example, it scientists understand the composition of rocks and soil on mars and can also be used to produce thermal energy. scientists have succeeded in producing many curium compounds, such as curium dioxide and curium chloride. these compounds are also used primarily in scientific research.

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?