Hung is the past tense of hang, for example "She hung her washing out on the line".
A rung is a step of a ladder. Ladders are usually made up of many rungs. Rung is also the past tense of ring.
Your tongue is a very strong muscle inside your mouth. It is covered in taste buds which let you taste your food. Your tongue is very important for talking with, and of course you can use it for making faces at people!