Important Discoveries in Chemistry

Important Discoveries in Chemistry

Introduction - Chemistry at the Start of the 20th Century

By 1900, chemistry had come a long way from its origins in medieval times with the alchemists. The understanding of the elements and chemical reactions had become a distinct science separate from natural philosophy, or physics as it is now known. The existence of the atom was still in dispute, although most scientists accepted it as a useful concept. The first subatomic particle, the electron, had been discovered, but scientists did not fully understand what they had found (Baum, 2003).

Many new elements had been discovered in the 19th century and a system for their classification had been established. It was called the periodic table and was constructed by placing the elements in order of increasing atomic weight, the assumption being that this was the property that characterized an element. The elements were arranged in columns such that similar chemical properties occurred at fixed intervals or periods. Sometimes this arrangement could not be made to work and so gaps were left in the table, anticipating the discoveries of new elements. The search for the missing elements had led to the discovery of new radioactive members of the table. However, isolating these elements for study had proven to be difficult and so little was known about them (Berube, 2004).

Also in the 19th century, chemical production had become an integral part of industrialized society. The majority of the technology had evolved in Germany where the availability of huge coal reserves had influenced the development of the industry. There, chemists had concentrated on the conversion of coal to produce chemicals. A disadvantage with this approach was that the industrial processing of crude oil, or petroleum, was totally neglected in Europe. One class of compounds that were not produced by coal-conversion were the unsaturated hydrocarbons from which synthetic plastics are produced. The development of plastics would have to wait for the rise of the mighty US petrochemical industry.

In 1828, German chemist Friedrich Wöhler (1800-1882) had produced the organic chemical urea using only inorganic starting materials, something thought impossible at the time. Synthesis, the artificial production of a substance from its constituents, had been restricted to inorganic compounds, but now new doors had been opened to the chemist. Progress was hampered by having no reliable techniques to examine how a substance was chemically constructed, leaving the synthetic chemist to stumble blindly through the jungle of chemical preparations, occasionally stumbling onto the correct path. Progress relied on individual breakthroughs rather than systematic development. Consequently, by the start of the 20th century, synthetic dyes were the only organic compound in full commercial production.

Chemistry was on the brink of a scientific and industrial explosion of development, which would see the discovery of wonders and the creation of nightmares to make society pause to consider whether it had chosen the right path (Atterwill, 1999).

The Atom - Physicists Lend A Hand

At the beginning of the 20th century, the concept that matter was composed of ...