A curved lined graph is shown. The y axis of the graph has the title Potential Energy. The x axis of the graph has the title Reaction Pathway. The graph curve begins at a higher level and ends at a slightly lower level. A vertical line labeled A, starting from the x axis till the beginning of the graph line is shown. A vertical line labeled B, starting from the x axis till the uppermost hump in the graph curve is shown. Another vertical line labeled C is shown from starting from the x axis till the point where the graph curve ends. Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give reasons in support of your answer. Part 2: Describe how you can determine the total change in enthalpy and activation energy from the diagram and if each is positive or negative.

the answer is a

photosynthesis

b is the correct answer

mark me brainliest and hope this

we need the questions , i may then you.

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.