A copper block (20°C) is placed in contact with a lead block (30°C), which is already in contact with an iron block (70°C). What will happen in this situation?

Heat will flow from the iron to the lead and from the lead to the copper until the temperatures are equal.

Heat will flow from the copper to the lead and from the iron to the lead until the temperatures are equal.

Heat will flow from the copper to the lead to the iron until the temperatures are equal.

Heat will flow from the lead to the copper and to the iron until the temperatures are equal.

iron and sleel

make siroeel

catya that's not even a b or c

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.