Main sequence stars are responsible for the formation of many elements. Which of the following best describes the process that forms these elements ? A
Energy is consumed to break heavy elements into hydrogen and helium
Reactive molecules combine with oxygen in a combushin reaction.
B.
CO
Fusion causes isotopes of hydrogen to combine into helium, releasing energy and neutrons
D.
Subatomic particles are drawn together by gravity, producing radioactive decay.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

answerca air mass;

the correct answer would be b) volume versus temperature, because they are also directly proportional.