They erupt due to the heat underground because of magma, building enough pressure for water to hit it's boiling point. When the pressure causes the water to come to the surface, the pressure is released cause a massive boil over, This ejects all the water in the reservoir to the surface in a boiling plume, creating a geyser
all the law is saying is that matter cant be created nor destroyed, so if 18 oxygen atoms are used, there will be 18 oxygen atoms in the end, no matter what, doesn't matter what they use it for or what
