Answer:
Four layers
Step-by-step explanation:
There are total four layers of Neptune. These four layers are - core, mantle, atmosphere, and upper atmosphere
a) Core – It is made up of rock and ice
b) Mantle – It is made up of water, ammonia, and methane ices.
c) Atmosphere – It is made up of hydrogen, helium, and methane gas
d) Upper Atmosphere – It has trace amount of helium