Answer the following question given this paragraph: Valence bond theory describes the benzene molecule and other planar aromatic hydrocarbon molecules as hexagonal rings of sp2-hybridized carbon atoms with the unhybridized p orbital of each carbon atom perpendicular to the plane of the ring. Three valence electrons in the sp2 hybrid orbitals of each carbon atom and the valence electron of each hydrogen atom form the framework of bonds in the benzene molecule. The fourth valence electron of each carbon atom is shared with an adjacent carbon atom in their unhybridized p orbitals to yield the bonds. Benzene does not, however, exhibit the characteristics typical of an alkene. Each of the six bonds between its carbon atoms is equivalent and exhibits properties that are intermediate between those of a CC single bond and a C = C double bond. To represent this unique bonding, structural formulas for benzene and its derivatives are typically drawn with single bonds between the carbon atoms and a circle within the ring as shown in Figure 20.11. Q: Which theory describes the benzene molecule and other planar aromatic hydrocarbon molecules as hexagonal rings of sp2-hybridized carbon atoms with the unhybridized p orbital of each carbon atom perpendicular to the plane of the ring? Choices: - hybrid orbital theory - covalent bond theory - molecular orbital theory - valence bond theory A:
valence bond theory
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Answer the following question given this paragraph: The fruiting bodies are usually produced at the surface of the food source, rather than hidden within it. This allows the reproductive spores to be easily shed and carried away by the wind, water, or animals. The fruiting bodies are usually the only indication that a fungus is present. Like icebergs, the fruiting bodies represent only a tiny fraction of the whole fungus, with most of the fungus hidden from view. Q: Where is the fruiting body normally produced in relation to the food source? Choices: - at the root - in the soil - underneath the surface - at the surface A:
at the surface
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Answer the following question given this paragraph: When an acid and a base react, the reaction is called a neutralization reaction . That's because the reaction produces neutral products. Water is always one product, and a salt is also produced. A salt is a neutral ionic compound. You can learn more about salts and how they form at this URL: http://www. youtube. com/watch?v=zjIVJh4JLNo . Q: What is the reaction called when an acid and a base react? Choices: - activation - oxidation - decomposition - neutralization A:
neutralization
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Answer the following question given this paragraph: Q: What is the process that breaks down rocks into smaller pieces? Choices: - erosion - bracing - bleaching - weathering A:
weathering
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