Answer:
I go in hard, come out soft. Blow me hard and I'll make a pop. What am I?
I am an instrument capable of making numerous sound but cannot be touched or seen.
I am easy to waste. I am unstoppable. What am I?
With three leaves, I am just a plant. Add another leaf and everyone will want me for good luck. What am I?
I am rarely touched but often held and if you are smart you'll use me well.
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.