The table below shows the fossils found in various layers of an undisturbed rock: fossils in rock layers layer (from top) fossil in layer 1 a, c 2 e 3 a, d, f 4 b 5 f, c 6 d, b which is most likely an index fossil?

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

i belive it is water