Answer:
D
Explanation:
The valence electrons are the outer electrons and must be located in the outermost shell. In this case, D.
The answer is C :
It controls the entry and exit of substances.
Answer:
Use the Bromotriflouride catalyst, BF₃
Explanation:
The BF₃ is most likely to yield less desired side products. The effect lies in the reaction mechanism.
BF₃ is a Lewis acid. Its role is to promote the ionization of the HF. This is achieved through the electrophilic mechanism. The reaction mechanism is as follows:
2 - methylpropene + H-F-BF₃ → H-F + H₃C + benzene
butylbenzene + F-BF₃ → tert-butylbenzene + H-F + BF₃ (regenerated catalyst)
Right now it's written in scientific notation, so you can just move the decimal place in 3.8 to the right 3 times (as it is times 10 to the third power) to get 3,800g.