Some of the gases in Earth's atmosphere, such as CO2, are called greenhouse gases. Greenhouse gases interact with sunlight in a way that traps heat in the atmosphere. By trapping heat, greenhouse gases help insulate Earth. The table below lists some important greenhouse gases and their atmospheric concentrations in units of parts per million (ppm), parts per billion (ppb), or parts per trillion (ppt).

Greenhouse gas Concentration in 2015

Carbon dioxide (CO2) 400 ppm

Sulfur hexafluoride (SF6) 9 ppt

Methane (CH4) 1,750 ppb

Nitrous oxide (N2O) 325 ppb

Use the data in the table to put the following greenhouse gases in order of atmospheric concentration.

Hint: A concentration of 1 ppm is 1,000 times more than 1 ppb, and 1 ppb is 1,000 times more than 1 ppt.

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.