When you watch a sunset, is the Sun really moving across the sky? What's happening?
(Science)

It's actually the Earth rotating around the sun. not the sun because the sun is in the middle according to the heliocentric model (the one that we use)

Explanation:

i'm wiling to try and you : )

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.