Answer:
Several events from the 4th to 6th centuries mark the transitional period during which the Roman Empire's east and west divided. In 285, the emperor Diocletian (r. 284–305) partitioned the Roman Empire's administration into eastern and western halves.
Explanation:
His discovery of the role of oxygen. He recognized and named oxygen and hydrogen and opposed the phlogiston theory. He helped construct the metric system, wrote the first extensive list of elements, and helped to reform chemical nomenclature.
