Blood is classified as a mixture. This is because it is composed of different components that can be separated from one another. The primary components of blood include red blood cells, white blood cells, platelets, and plasma. Each of these components has distinct functions and properties.
A compound, on the other hand, consists of two or more elements that are chemically bonded together. An example of a compound would be water (H2O), where hydrogen and oxygen are chemically combined in fixed proportions. In blood, the various cellular components and plasma maintain their individual characteristics and do not undergo chemical changes to form a new substance.
In summary, since blood retains its individual components that can be physically separated, it is best described as a mixture rather than a compound.