In a swimming pool, the pH is 5.5. The pH is supposed to be 7.0 for the safety of the swimmers. What should be added to the pool to reach the desired pH?

Asubstance is held in an open container. its particles move past one another at random speeds but do not leave the container. heat is removed from the system, and the particles slow down. when enough heat is removed, the particles no longer have enough speed to overcome the weak attractive forces between them. when this happens, the substance enters its solid state. the process described above is known as .