What is the name of the new planet that replace the planet Pluto?
Nothing replaced Pluto – Pluto still exists. It is now just called a dwarf planet, and not a planet anymore. The difference between dwarf planets and planets is just one attribute: Planets concentrate most of the mass in their orbital region inside them. Pluto is just one object among many inside the Kuiper Belt, that’s why it is no longer considered a planet. Physically, nothing changed. All is the same as always. We just use a new label for Pluto.