There are different degrees to which products or services can be defined as substitutes. A perfect substitute is a product or service that can be used in the exact same way as the good or service it replaces. This is where the utility of the product or service the exact same.
Medicine Pouches Activity. This Activity is meant for Cub Scouts. Medicine pouches made from leather and used by Indians to store meaningful items they had collected during their life. The pouch was hung around the neck or off the belt and would be decorated individually. Stories are more fun when there is a totem handed out that symbolizes the story.
In order to take this interaction into account, the ion activity, also known as the effective ion concentration, must be considered rather than ion concentration. As a result, pH is a measure of hydrogen ion activity. The activity coefficient is a function of the ion concentration and approaches 1 as the solution becomes increasingly dilute. Therefore, hydrogen ion concentration and hydrogen ion activity are nearly equal in very dilute samples. In samples with high ion concentration, ion activity becomes much lower than concentration (i.e. apparent loss of ions). YSI offers a variety of platforms for the measurement of pH.