At constant pressure and volume, the density of a gas as the molar mass increases. A gas made of heavier particles will have a density than a gas composed of lighter particles under the same conditions of temperature and pressure.

Increases, higher

Explanation:

Remember that the formula for Density is D=mass/volume.

If volume remains the same, as mass increases the density will also increase as the numerator of this math problem increases while the denominator remains the same.

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.