Philosophy: How can one interpret the variation in the nature of matter (as is evident from experimental evidence of different elements and that follows from theory of atomic nature) IN TERMS OF A PRIORI STRUCTURES OF MIND/INTUITION (As Kant puts them)?
Kant’s philosophy is about the limits of experience and especially reason, and does not explain per se the variation of experiences themselves. This is covered by the category of Quality, which gives us ways of understanding qualitative differences. But as far as I know where the qualitative differences come from is not discussed. It is just assumed that if the variety production did not occur then there would be no experience as such.