Which is the energy source used to fuel photosynthesis?
O
O
O
sunlight
glucose
carbon dioxide
water

catya your not at all which answer i've seen you do this on another question!

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.