slime like entity

i'm making a custom entity and using a slime as a base, and then making an armor stand with an item with custom model in it's head that teleport to it. I would like to verify if two things are possible: first is possible to remove the particles the slime emits when it bounces or lands? and it's possible to detect if the slime is on ground or not, maybe i can use this velocity y but i would like to know if there's an better method thanks