Household cleaning agents such as ammonia, borax, lye, and detergents are common examples of bases. Many different kinds of acids and bases are used by scientists. The pH of a liquid tells whether it is an acid or a base and how weak or strong it is. A liquid can have a pH number from 1, the stongest acid, to 14, the strongest base. Any solution with a pH less than 7 is an acid, while a solution with a pH greater than 7 is a base.
Pure water is one of the few substances whose pH is seven.
A solution with a pH of 7 contains equal numbers of hydrogen atoms and hydroxyl groups, so it is neither an aicd nor a base, but chemically neutral. Below is a sample exercise to show you how to do this part of the examination. The answer is Newton. In the answer row of circles the circle with a D in the center would be blackened. In Part V there are statements that concern how you feel about yourself and certain situations in relation to a potential work environment.