pH is an important parameter for many reactions to take place in solution and in biological systems. It is related to the concentration of H⁺ ions through the following expression:
pH = 1/[H⁺] = -log [H⁺]
Wanting to know the pH of a solution is equivalent to knowing the amount of hydrogen ions present. But the pH scale is more convenient than the concentration scale because pH usually takes values between 0 and 14.
- When pH < 7 the solution is acid.
- When pH = 7 the solution is neutral (like pure water).
- When pH > 7 the solution is basic.
The statement that correctly compares protons, electrons, and neutrons is, "Quarks are present in protons and neutrons but not in electrons". Quarks are tiny particles which compose the neutrons and protons. These quarks in protons and neutrons are linked together by gluons.
The lowest point of a wave is called trough.
