When Apollo 15 astronaut David Scott did his famous free fall experiment on the moon, he dropped a falcon feather from a height of about 1.6 meters. Assuming a gravitational acceleration of 1.6 m/s on the moon, about how long did it take the feather to drop to the surface? A) 1.0 seconds
B) 1.4 seconds
C) 1.6 seconds
D) 2.0 seconds

explanation:

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.