We can go way back the 500’s BC to find theories developing on the concept of atoms. To streamline, let’s start with John Dalton, the first scientist to truly organize elements using the characteristics those of atoms. By experimenting with numerous gases, he observed that the elements that made up the chemical combined in specific ratios. He deduced this by weighing their individual masses. Further employing deductive reasoning, he put together “rules” to describe/predict how elements combine to form chemicals and more specifically, that they combine in specific ratios.
Rather than drawing my own illustration of Dalton’s Atomic model, I felt these original images of Dalton’s would be more impactful to begin our journey. More than a simple list of various elements, Mr. Dalton begins to notice patterns of "behavior" with certain groups of elements, and thus organizes them visually by these characteristics. This will become the prototype for the periodic table.