what is the difference between two atoms of carbon having the same number of neutrons?

a.
nothing

b.
the number of protons

c.
the number of electrons

d.
there may be differences in how they react with oxygen

D because they actually may be differences

D.
there may be differences in how they react with oxygen

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.