Q: What term decribes the amount of time required for half of the original material to decay in an isotope?   Read this paragraph and choose the correct option from the provided answers:  11.6 End-of-Chapter Material Chapter Summary To ensure that you understand the material in this chapter, you should review the meanings of the bold terms in the following summary and ask yourself how they relate to the topics in the chapter. Some atoms have unstable nuclei that emit particles and high-energy electromagnetic radiation to form new elements that are more stable. This emission of particles and electromagnetic radiation is called radioactivity. There are three main types of spontaneous radioactive emission: alpha particles, which are equivalent to helium nuclei; beta particles, which are electrons; and gamma radiation, which is highenergy electromagnetic radiation. Another type of radioactive process is spontaneous fission, in which large nuclei spontaneously break apart into smaller nuclei and, often, neutrons. In all forms of radioactivity, new elements are formed from the radioactive reactants. Radioactive isotopes decay at different rates. The rate of an isotope’s decay is expressed as a half-life, which is the amount of time required for half of the original material to decay. The length of its half-life is a characteristic of the particular isotope and can range from less than microseconds to billions of years. Amounts of radioactivity are measured in several different ways. A becquerel is equal to one radioactive decay per second. A curie represents 3.7 × 1010 decays per second. Other units describe the amount of energy absorbed by body tissues. One rad is equivalent to 0.01 joule of energy absorbed per gram of tissue. Different tissues react differently to different types of radioactivity. The rem unit takes into account not only the energy absorbed by the tissues, but also includes a numerical multiplication factor to Saylor URL: http://www. saylor. org/books.   Choices:  - radioactive isotope  - Geiger count  - life cycle  - half-life   A:
half-life
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Q: In what ocean is the mid-atlantic ridge located?   Read this paragraph and choose the correct option from the provided answers:  There is a lot of volcanic activity at divergent plate boundaries in the oceans. As the plates pull away from each other, they create deep fissures. Molten lava erupts through these cracks. The East Pacific Rise is a divergent plate boundary in the Pacific Ocean ( Figure below ). The Mid-Atlantic Ridge is a divergent plate boundary in the Atlantic Ocean.   Choices:  - indian ocean  - pacific ocean  - arctic ocean  - atlantic ocean   A:
atlantic ocean
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Q: The release of mature eggs that occurs at the midpoint of each cycle is called?   Read this paragraph and choose the correct option from the provided answers:     Choices:  - fertilization  - induction  - semination  - ovulation   A:
ovulation
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Q: When does sublimation occur?   Read this paragraph and choose the correct option from the provided answers:  Sublimation occurs when ice and snow change directly to water vapor. This also happens because of heat from the sun.   Choices:  - when the wind changes direction  - when the snow melts the ice caps  - when the ice and sand change directly into water vapors  - when the ice and snow change directly into water vapors   A:

when the ice and snow change directly into water vapors
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