Answer the following question given this paragraph: Life on Earth is very diverse. The diversity of living things is called biodiversity . A measure of Earth's biodiversity is the number of different species of organisms that live on Earth. At least 10 million different species live on Earth today. They are commonly grouped into six different kingdoms. Examples of organisms within each kingdom are shown in Figure below . Q: What is the diversity of living things called? Choices: - degradation - life cycle - ecosystem - biodiversity A:
biodiversity
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Answer the following question given this paragraph: Note Today, new elements are usually named after famous scientists. The names of the elements can be cumbersome to write in full, especially when combined to form the names of compounds. Therefore, each element name is abbreviated as a one- or two-letter chemical symbol. By convention, the first letter of a chemical symbol is a capital letter, while the second letter (if there is one) is a lowercase letter. The first letter of the symbol is usually the first letter of the element's name, while the second letter is some other letter from the name. Some elements have symbols that derive from earlier, mostly Latin names, so the symbols may not contain any letters from the English name. Table 2.3 "Element Names and Symbols" lists the names and symbols of some of the most familiar elements. Table 2.3 Element Names and Symbols. Q: Today, new elements are usually named after famous scientists. the names of the elements can be cumbersome to write in full, especially when combined to form the names of compounds. therefore, each element name is abbreviated as a one- or two-letter chemical this? Choices: - notation - title - shorthand - symbol A:
symbol
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Answer the following question given this paragraph: Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves is called the electromagnetic spectrum. It is outlined in the following Figure below . Q: What kind of waves consist of vibrating electric and magnetic fields? Choices: - gaseous waves - sound waves - hydraulic waves - electromagnetic waves A:
electromagnetic waves
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Answer the following question given this paragraph: The Dutch scientist Christiaan Huygens (16291695) developed a useful technique for determining in detail how and where waves propagate. Starting from some known position, Huygens's principle states that: Every point on a wavefront is a source of wavelets that spread out in the forward direction at the same speed as the wave itself. The new wavefront is a line tangent to all of the wavelets. Figure 27.5 shows how Huygens's principle is applied. A wavefront is the long edge that moves, for example, the crest or the trough. Each point on the wavefront emits a semicircular wave that moves at the propagation speed v . These are drawn at a time t later, so that they have moved a distance s = vt . The new wavefront is a line tangent to the wavelets and is where we would expect the wave to be a time t later. Huygens's principle works for all types of waves, including water waves, sound waves, and light waves. We will find it useful not only in describing how light waves propagate, but also in explaining the laws of reflection and refraction. In addition, we will see that Huygens's principle tells us how and where light rays interfere. Q: Dutch scientist christiaan huygens' principle of what states that every point on a wavefront is a source of wavelets that spread out in the forward direction at the speed of the wave itself? Choices: - electromagnetic dynamics - energy propagation - wave dynamics - wave propagation A:
wave propagation
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