  Before it rains, if using granular fertilizer, so that it will melt into the soil and become available for use by the plant roots.....IF you are using liquid fertilize â¦ r you would apply it either on the leaves, or by drenching the soil around the plant at least 24 hours before a rain occurs. Before it rains, if using granular fertilizer, so that it will melt into the soil and become available for use by the plant roots.....IF you are using liquid fertilize â¦ r you would apply it either on the leaves, or by drenching the soil around the plant at least 24 hours before a rain occurs.
Physical and Chemical Changes. There are several differences between a physical and chemical change in matter or substances. A physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. For example, if a piece of paper is cut up into small pieces it still is paper. This would be a physical change in the shape and size of the paper.
So, in summary, there are really only two criteria for whether a change is chemical or physical: 1) After the change does it look the same and 2) can you change it back? If the answer is yes, the change is physical every time. If the answer is no the change is chemical every time.