The answer is 67.82 g/mol
B. He would be considered an Organic Chemist since Organic Chemistry is the study of Carbon and its compounds.
This example is an controversial matter because melting an candle is considered as both physical change and chemical change because no new substances were made by melting an candle. The final answer is C.
I would say that if they would use the regular ones, they would not be able to see very far. as well with that i would add that they need special lenses to see far.
hope that this helps you! =)