Well you want the answer with the same letter in it. A.k.a 2. This means they have the same element in them
O2 (Diatomic oxygen that we breathe) and O3 (Ozone that would be deadly to breathe) have different structures.
So the answer is 2
Since none answered from Indian NCERT yet, let me give a simple definition from ICSE..
Latent Heat of vapourisation is the heat energy required to convert unit mass of a substance from liquid to vapour state WITHOUT ANY CHANGE IN ITS TEMPERATURE....
hope this helps!
NH3 + H2O -> NH4+ + OH- is the answer I think I just did this in class today
