Why is pluto no longer considered a plant in our solar system

Its size.

its now a dwarf planet due to that fact,

also the fact of how far away it is fro the sun, as its on the outskirts of our galaxy

scientist said it was not considered a planet because it  -has not cleared its neighboring region of other objects.”

idk what the options are but

these is a strong electrostatic attraction between the ions hence a lot of energy is needed to overcome this attraction

this is why the boiling points are so high