What can you learn from the atomic number? a The combined number of protons and neutrons an atom has. b The number of neutrons found in the nucleus of an atom. c The number of electrons found in an atom's outer shell. d The number of protons found in the nucleus of an atom.

The answer is d

Explanation:

The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element.

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.

you need to stop taking that class