Which statement best describes physical properties? A. Physical properties behave identically for all matter under the same conditions.
B. Physical properties can be observed without changing the identity of a substance. C. Physical properties are observed by seeing how a substance reacts with other substances.
D. Physical properties cause atoms and molecules to change structure when substances are mixed.

i think its 5049.

i hope this !

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.

level 4 to level 2 : ))