In which two ways does a balanced chemical equation model the law of conservation of mass?
A. The total mass of the reactants equals the total mass of the
products.
B. The total mass of the metals involved equals the total mass of
nonmetals.
C. The reactants are the same substances as the products.
D. The same numbers and types of atoms appear on both sides of
the equation.

astronomers such as edwin hubble.

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.