Answer:
Lighter than what I am made of. More of me is hidden than seen. What am I?
I am a daily ritual involving using a metal tool on the body
I have three feet but I cannot walk. What am I?
You are my brother, but I am not your brother. Who am I?
I have a straight back and sharp teeth to cut objects.
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.