Book 30, Question 125
Can water ever be perfectly pure?
But in nature, water dissolves and carries bits of everything it touches, like minerals, gases, and tiny particles.
In a lab, scientists can make water that is extremely close to pure H2O. Even rain picks up dust and gases from the air. Totally pure water is also not best for drinking, since our bodies get some minerals from water. The goal is water that's clean and safe, not perfect.