(Question)
Q: The uranium series is a chain constituting one what, which encompass naturally occurring isotopes of the heaviest elements? Read this paragraph and choose the correct option from the provided answers: Radioactive Decay Series The naturally occurring radioactive isotopes of the heaviest elements fall into chains of successive disintegrations, or decays, and all the species in one chain constitute a radioactive family, or radioactive decay series. Three of these series include most of the naturally radioactive elements of the periodic table. They are the uranium series, the actinide series, and the thorium series. The neptunium series is a fourth series, which is no longer significant on the earth because of the short half-lives of the species involved. Each series is characterized by a parent (first member) that has a long half-life and a series of daughter nuclides that ultimately lead to a stable end-productthat is, a nuclide on the band of stability (Figure 21.9). In all three series, the end-product is a stable isotope of lead. The neptunium series, previously thought to terminate with bismuth-209, terminates with thallium-205. Choices: - nuclear decay family - gland decay family - fuel decay family - radioactive decay family A:
(Answer)
radioactive decay family

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Q: What is the term for something left behind by once-living organisms? Read this paragraph and choose the correct option from the provided answers: Most sedimentary rocks form from sediments. Sediments are small pieces of other rocks, like pebbles, sand, silt, and clay. Sedimentary rocks may include fossils. Fossils are materials left behind by once-living organisms. Fossils can be pieces of the organism, like bones. They can also be traces of the organism, like footprints. Choices: - decay - waste matter - deposits - fossils A:
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fossils

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Q: What is transmitted by moving electrons in an electric current? Read this paragraph and choose the correct option from the provided answers: Electrical energy is transmitted by moving electrons in an electric current. In order to travel, electric current needs matter. It cannot pass through empty space. However, matter resists the flow of electric current. That's because flowing electrons in current collide with particles of matter, which absorb their energy. Some types of matter offer more or less resistance to electric current than others. Choices: - potential energy - subsequent energy - stellar energy - electrical energy A:
(Answer)
electrical energy