The element carbon, nitrogen, and oxygen are all part of the same?

If 1.8 l of water is added to 2.5l of a 7.0 molarity koh solution, what is the molarity of the new solution

Why does his teacher ask him to balance the equation by including the correct coefficient

In the particles are arranged in a regular, repeating pattern. a)a crystalline liquid b)a crystalline solid c)all gases d)all solids