What is the relationship between the two structures shown ?

What is the relationship between the structures shown ?

What is the relationship between the structure below?

What is the relationship between the structure below?

What is the relationship between the two species shown below? overset(..)underset(..)N=N=overset(..)underset(..)O" ":N-=N-overset(..)underset(..)O: They are :

What is the relationship between the following two structures ?

What is the relationship between the following two structures ?

What is the relationship between the given structures (look at the arrow)?

What is the relationship between the given structures (look at the arrow)?

What is the relationship between the structure of hydrocarbons used as fuels and their octane numbers ?

What is the relationship between two molecules?