Understanding Avogrado's hypothesis I have read that gases under identical conditions of temperature, pressure, and volume contain the same number of molecules, but every gas has different types of atoms so their force of attraction is also different then how can this be true?
If we consider **Ideal gas equation **
and ignore the type of interaction which are present in the real gases then ; 
$PV=nRT $
wherevP= pressure ; v=vol. ; n= moles; R = universal gas constant ; T= temp.

$PV/RT=constant $
so $n=constant$

so if$ n$ is constant then if we multiply it with avogadro's constant $N_A $ it would give you number of molecules .
Again that's when ideal gas .