Energy may be defined as the heat content of an object.

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

gas

explanation:

smoke is the matter of a gas

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.