[Chemistry Form 4] Forming Theories

Man's first step in modern chemistry probably dated back to the discovery of fire. Thanks to it, man could cook food, make glass and also extract metals from ores.

Man was so content with the results of what they had done that they did not try to explain what had happened or why something had happened.

Only two thousand and five hundred years ago, philosophers began to question what things are made of, and what happens when things change.

The following is a brief history of chemists who had pondered about matter;

1. It was the 5th century BC in Greece. Empedocles suggested that all things on Earth are made from four fundamental substances he called elements. What were these four elements?
   
   • Fire, water, air and earth.
     
     
2. Another Greek philosopher, born at the time Empedocles died, proposed that nature is made up of tiny particles he called atoms, which, in Greek, means indivisible. Who was this Greek philosopher?
   
   • Democritus.

The atomic hypothesis was contested by the greatest philosopher at the time who remained faithful to the element theory. Because of his great reputation, the false element theory dominated scientific thought for two thousand years. Who was this famous Greek philosopher?

• Aristotle.

In later years, history has it that the Alexandrians were the first to devote themselves to alchemy, and they were soon followed by the Arabs, who introduced it into Western Europe. When was this?

• 4th century AD.

Chemistry then made little headway for years. In 1525, a Swiss doctor and scientist challenged his students to tear up their books, which recorded old theories that had been developed through reasoning, and told them to find out for themselves through experiments whether a scientific theory was right or wrong. This scientist had an imposing name. Who was this scientist?

• Theophrastus Bombastus Paracelsus Von Hohenheim.

Later on, Robert Boyle, an Englishman, succeeded in killing off the old idea of the four elements by establishing that there are other elements - substances that cannot be formed by or broken into other substances. When was this?

• 1661

A hundred years after Boyle made his discovery, a Swede, Karl Scheele, and an Englishman, Joseph Priestley, succeeded in isolating oxygen. Modern chemistry was thus born.