Which of the following is stroring gravitational potential energy A. A baseball player sliding into home plate
B. A ballet dancer spinning on her toes
C. A cat stalking a mouse
D. A water bucket hanging over a well

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.