Question

what is the most important between wavelength and momentum of a particle

Answer 1

Wave–particle duality is the concept in quantum mechanics that every particle or quantic entity may be partly described in terms not only of particles, but also of waves. It expresses the inability of the classicalconcepts "particle" or "wave" to fully describe the behavior of quantum-scale objects. As Albert Einstein wrote:[1]

It seems as though we must use sometimes the one theory and sometimes the other, while at times we may use either. We are faced with a new kind of difficulty. We have two contradictory pictures of reality; separately neither of them fully explains the phenomena of light, but together they do.

Answer 2

Wavelength is the maximum distance that can be coverd by a given sound wave with the given time while momentum is the ratio between the distance coverd as compared to the time taken by a given particle. the most important thing isthw ti,me traken by both since distance nay be considered as constant in any give case.