If it weren't for newton's law, regarding inertia, the planets would travel in a straight line into space. gravity is the outside force that keeps the planets in orbit about the sun.

First law.
Hope this is the answer you seek

Ithink this is what you meant. the temperature at which a liquid begins to boil is called the boiling point. the boiling point of water is 212°f or 100°c.  and at that point will start to turn into steam (gas)