Theoretical and Experimental Aspects of Chemistry

Chemistry has two aspects, theoretical and experimental.

Historically, the experimental aspect seems to be older. In ancient times, people developed experimental techniques to use matter in different forms e.g., they developed the technique of extracting and using copper, iron, etc. In fact, copper is believed to be discovered more than 10,000 years ago. In such ancient times, people would naturally focus on useful knowledge rather than then hypotheses. And even they had some model about the transformations of matter in their heads, it would have been very difficult to express and leave the proof for us.

On the other hand, theoretical aspects started evolving as early as the time of Democritus (460-370 BC). Democritus assumed that everything was built up of tiny invisible particles, each of which was eternal and immutable. He called these particles atoms. This may be considered to be the first approach that tried to explain the types and transformations of matter theoretically.

Nowadays, we understand most of the natural phenomena, including chemical transformations, based on theoretical models rather than depending directly on our sense organs. But still, these theories are developed not just to make things complicated but to explain the experimentally observed phenomena. And these need to tally with all experimental findings.