Chemistry is the study of anything that has mass and occupies space gases, liquids, solids. It is the study of how these things act in different temperature ranges and under other differing conditions. It is the study of what makes up gases, liquids and solids.
Chemists study all things that have mass and occupy space, making chemistry the central science.
Stone Age man knew how to make the hide of a deer into clothing and boots. He also had tools that would have been applied to specific situations. A qualitative observation describes color, shape, temperature, size, smell or any other general observation. A quantitative observation counts the number of objects, measures the length and width, measures the mass or makes another kind of measurement. An educated guess or explanation of something you have seen.