Carbon has a neutral overall charge, an atomic mass of about 12 and an atomic number of 6. how many electrons does carbon have?
a. 3
b. 6
c. 12
d. 24

The correct answer is B. 6

Explanation:

Each atom of an element is composed of a certain amount of protons, electrons, and neutrons. In the case of electrons, the number of electrons is the same as the protons in the case of atoms that are neutrally charged. Additionally, the atomic number of an atom indicated the number of electrons in it and the atomic mass the number of electrons and protons together.

This means by knowing the number of protons which in this case is 6 (Atomic number) and the atomic mass which is 12 it is possible to determine the number of electrons. Either because the number of electrons is the same that the number of atoms which means is 6 or the atomic mass minus the protons are the number of electrons, which is also 6 (12-6 = 6).

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.