24) electron configurations indicate the location of each electron within the atom. there are rules that must be
followed when writing an electron configuration. one of the rules deals with the order that the electrons enter
the orbitals. this rule states that the electrons are added to orbitals of increasing energy, beginning with the
lowest energy orbitals and continue doing so until all electrons are placed. which rule is this known as?
a) bohr's rule
b) hund's rule
c) aufbau principle
d) pauli exclusion principle

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.

c. orbital shape i hope this is correct

plasma - state of matter made up of electrically charged particles