Perfluorocarbons are
A) hydrocarbons in which all hydrogen atoms have been replaced by fluorine.
B) hydrocarbons in which most hydrogen atoms have been replaced by fluorine.
C) hydrocarbons in which there is one fluorine per carbon atom.
D) none of the above
Question 2
Which of the following gases is most efficient at trapping atmospheric heat?
A) carbon dioxide (CO2)
B) nitrogen trifluoride (NF3)
C) water (H2O)
D) methane (CH4)