Condition for formation of ionic bond

[gracy]

In my textbook one of the conditions for formation of ionic bond is given as
The cation should be large and anion should be small
But in the image of Nacl lattice structure ,we can see that it is other way around

I am not getting the reason,Is my textbook wrong ?
Or it has something to do with difference between ionic bond and lattice structure.I mean the picture I have attached is of crystal lattice not of single ionic bond between Sodium and chloride ion.

Thanks.

 

[gracy]

But in the image of Nacl lattice structure ,we can see that it is other way around

 

[Borek]

In my textbook one of the conditions for formation of ionic bond is given as
The cation should be large and anion should be small

Pure nonsense, no such condition.

Additionally, there is no such thing as a "single ionic bond" and a "single ionic molecule". All pure ionic substances exist only as ionic crystals (well, is some highly exotic conditions you can observe single molecules, it doesn't change the validity of the general statements).

 

[gracy]

Pure nonsense, no such condition.

That means my textbook is wrong.

 

[Borek]

Looks like.

 

[gracy]

And there is no such condition as
anion should be large and cation should be small either,right?

 

[Borek]

No, sizes don't matter at all.

They matter when it comes to the type of the lattice that they will build, but that's another story.

 

[gracy]

hmm...Thanks @Borek