Dehydrate
Erase.
A prefix that means "remove" can be ex- I.E. Exclude - Remove from inclusion or Excavate - Remove from the ground or other spot ----------------------------------------------------------------------------------------------- and sometimes the word can start with "de-". This is also a prefix that means "remove".
What word means a small body of water
To take away or take off (Remove your shoes) or delete (Remove that word from your sentence)
Circumnavigate is the word that means to travel around the world by water.
The word "dehydration" means loss of water, from the Greek root hydro (water).
Being hydrophobic means to hate water or to have a fear of water.
Earth's hydrosphere is made up of water because the word hydro means water and the word sphere means circular, so hydrosphere means Earth's water or water on Earth.
The word dehydrate means to remove water. Chemicals without water are sometimes described as anhydrous (if they usually have water). This does not particularly relate to writing a number in front of the formula for water, but I could indicate an absence of water by saying there is zero H2O.
grab, pull, remove
Earth's hydrosphere is made up of water because the word hydro means water and the word sphere means circular, so hydrosphere means Earth's water or water on Earth.