The highest level of scientific experiment is known as experimental, or randomized control. In this type, as the name implies, there is the greatest amount of control. There are at least two groups used in this type of scientific experiment. Each group is made up of subjects that resemble each other as close as possible, such as by age, gender, etc. Subjects can be human, animal or the environment.
Chemical changes can result from the combination of different substance through a reaction to give one or more different substances. Decomposition, the opposite of combination, involves the breakdown of a single substance into two or more different substances.
A chemical change involves the change in a substance through chemical reactions. The chemical reagents form a new product with equal mass. The following is a list of evidence that can indicate that a chemical change took place.Note that this evidence is not conclusive.est Answer: I suppose you mean examples of five physical and chemical changes: Chemical changes-rusting of iron, curdling of milk, yellowing of newspapers left in the Sun, darkening of apples, melting of butter, digestion of food and fermentation of grapes into wine.