need help with 1-4 please

1. Briefly explain the difference between a chiral center and a stereocenter. 2. How many constitutional isomers are there for C8H18 ? 3. There are two chiral centers in one of the constitutional isomers of C8H10 and four other isomers have one chiral center each. Clearly indicate which carbon(s) in at least 4 stereoisomers which qualify as chiral centers. Example: C\#3 in 2,2,3-trimethylpentane C in C\# in C \# in C \# in 4. Classify each pair of molecules as constitutional (C), diastereomers (D), or enantiomers (E). a. b