Answer the following question given this paragraph:   a reductant or an oxidant; it is also a Lewis base. The other reactant (Cl2) is an oxidant, so we expect a redox reaction to occur in which the carbon of CO is further oxidized. Because Cl2 is a two-electron oxidant and the carbon atom of CO can be oxidized by two electrons to the +4 oxidation state, the product is phosgene (Cl2C=O). Unlike Cl2, BF3 is not a good oxidant, even though it contains boron in its highest oxidation state (+3). Nor can BF3 behave like a reductant. Like any other species with only six valence electrons, however, it is certainly a Lewis acid. Hence an acid–base reaction is the most likely alternative, especially because we know that CO can use the lone pair of electrons on carbon to act as a Lewis base. The most probable reaction is therefore the formation of a Lewis acid–base adduct. Typically, both reactants behave like reductants. Unless one of them can also behave like an oxidant, no reaction will occur. We know that Sr is an active metal because it lies far to the left in the periodic table and that it is more electropositive than carbon. Carbon is a nonmetal with a significantly higher electronegativity; it is therefore more likely to accept electrons in a redox reaction. We conclude, therefore, that Sr will be oxidized, and C will be reduced. Carbon forms ionic carbides with active metals, so the reaction will produce a species formally containing either C4− or C22−. Those that contain C4− usually involve small, highly charged metal ions, so Sr2+ will produce the acetylide (SrC2) instead. Exercise.   Q: Carbon is a nonmetal with a significantly higher electronegativity; it is therefore more likely to accept electrons in what kind of reaction?   Choices:  - reversable reaction  - catalyst reaction  - isotope reaction  - redox reaction  A:
redox reaction
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Answer the following question given this paragraph:   A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. You can watch some very colorful chemical changes occurring in the video at this URL:.   Q: When matter changes into an entirely different substance with different chemical properties, what has occurred?   Choices:  - mechanical change  - gaseous change  - physical change  - chemical change  A:
chemical change
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Answer the following question given this paragraph:   Remember that individuals do not evolve. Their genes do not change over time. The unit of evolution is the population. A population consists of organisms of the same species that live in the same area. In terms of evolution, the population is assumed to be a relatively closed group. This means that most mating takes place within the population. The science that focuses on evolution within populations is population genetics . It is a combination of evolutionary theory and Mendelian genetics.   Q: What is the unit of evolution?   Choices:  - species  - community  - biome  - population  A:
population
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Answer the following question given this paragraph:   28.5 Red algae and green algae are the closest relatives of land plants.   Q: Red algae and green algae are the closest relatives of what?   Choices:  - transfer plants  - arctic plants  - water plants  - land plants  A:

land plants
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