The statement which best explains why carbon is present in so many kinds of molecules is because <u>it can form four covalent bonds.
<em /></u>It isn't rare on Earth, so A is incorrect. It has valence electrons, so C is incorrect. It cannot become an ion, so D is incorrect.<u>
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It regulates the body's growth, metabolism (the physical and chemical processes of the body) and sexual development and function.
5% of $20 is $1; 5% off $20 is $19
Salt marshes are primarily influenced by the tidal flow.
When a factory is emitting large
amounts of CFCs into the atmosphere, it affects the people in that area by the increase
in the level of ocean water. CFCs dissolve in seawater and because they are not
reactive, they just circulate until it becomes saturated.