Answer: BF3
Explanation: boron needs 4 electron to obtain octet and Fluorine has just one. For the valence shell to be completely filled it will have to form BF4- with 4 fluorine atom surrounding it.
The answer is -11.2 fahrenheit.
I don’t know the author or what book/literary work this is, but could be how proteins are produced.
The answer is d. natural gas. All the other choices are alternative sources of energy, and do not produce or emit any greenhouse gas such as carbon dioxide (CO2). Natural gas, on the other hand, is an organic substance containing a significant amount of carbon, that when burned for fuel, results in the emission of CO2.