Seminar Work

The development of Chemistry as a study throughout history

Pierre and Marie Curie in their laboratory prior to 1907.

Introduction
In many ways, the history of civilization is the history of chemistry — the study of matter and its
properties. Humans have always sought to identify, use and change the materials in our
environment. Early potters found beautiful glazes to decorate and preserve their wares.
Herdsmen, brewers and vintners used fermentation techniques to make cheese, beer and wine.
Housewives leached the lye from wood ash to make soap. Smiths learned to combine copper and
tin to make bronze. Crafters learned to make glass; leatherworkers tanned hides

Elaboration
In the eighth century A.D., Jābir ibn Hayyān, a Muslim astronomer,
philosopher and scientist, became one of the first to use scientific methods
to study materials. Also known by his Latinized name, Geber, he is known
as the "father of chemistry." He is thought to be the author of 22 scrolls
describing methods of distillation, crystallization, sublimation and
evaporation. He invented the alembic, a device used to distill and study
acids. He also developed an early chemical classification system using the
properties of the materials he studied. His categories were:
・“Spirits” — materials that would vaporize when heated.

・"Metals" — including iron, tin, copper, and lead.

・ "Non-malleable substances" — materials that could be made into powders, such as stone.

Today we might call similar materials “volatile chemicals, metals and non-metals.”

Classical chemistry
In Europe, the study of chemistry was conducted by alchemists with the goals of transforming
common metals into gold or silver and inventing a chemical elixir that would prolong life.
Although these goals were never achieved, there were some important discoveries made in the
attempt.
Robert Boyle (1627-1691) studied the behavior of gases and discovered
the inverse relationship between volume and pressure of a gas. He also
stated that “all reality and change can be described in terms of
elementary particles and their motion,” an early understanding of atomic
theory. In 1661, he wrote the first chemistry textbook, “The Sceptical
Cymist,” which moved the study of substances away from mystical
associations with alchemy and toward scientific investigation.
By the 1700s, the Age of Enlightenment had taken root all over Europe.
Joseph Priestley (1733-1804) disproved the idea that air was an indivisible element. He showed
that it was, instead, a combination of gases when he isolated oxygen and went on to discover
seven other discreet gases. Jacques Charlescontinued Boyles’ work and is known for stating
the direct relationship between temperature and pressure of gases. In 1794, Joseph Proust
studied pure chemical compounds and stated the Law of Definite Proportions — a chemical
compound will always have its own characteristic ratio of elemental components. Water, for
instance, always has a two-to-one ratio of hydrogen to oxygen.
Antoine Lavoisier (1743-1794) was a French chemist who made
important contributions to the science. While working as a tax collector,
Lavoisier helped to develop the metric system in order to insure uniform
weights and measures. He was admitted to the French Academy of
Sciences in 1768. Two years later, at age 28, he married the 13-year-old
daughter of a colleague. Marie-Anne Lavoisier is known to have assisted
her husband in his scientific studies by translating English papers and
doing numerous drawings to illustrate his experiments.
Lavoisier’s insistence on meticulous measurement led to his discovery of
the Law of Conservation of Mass. In 1787, Lavoisier published "Methods of Chemical
Nomenclature," which included the rules for naming chemical compounds that are still in use
today. His "Elementary Treatise of Chemistry" (1789) was the first modern chemistry
textbook. It clearly defined a chemical element as a substance that cannot be reduced in weight
by a chemical reaction and listed oxygen, iron, carbon, sulfur and nearly 30 other elements then
known to exist. The book did have a few errors though; it listed light and heat as elements.
Amedeo Avogadro (1776-1856) was an Italian lawyer who began to study
science and mathematics in 1800. Expanding on the work of Boyle and
Charles, he clarified the difference between atoms and molecules. He went
on to state that equal volumes of gas at the same temperature and pressure
have the same number of molecules. The number of molecules in a 1-gram
molecular weight (1 mole) sample of a pure substance is called Avogadro’s
Constant in his honor. It has been experimentally determined to be 6,023×
1023 molecules and is an important conversion factor used to determine the
mass of reactants and products in chemical reactions.
In 1803, an English meteorologist began to speculate on the
phenomenon of water vapor. John Dalton (1766-1844) was
aware that water vapor is part of the atmosphere, but
experiments showed that water vapor would not form in
certain other gases. He speculated that this had something to
do with the number of particles present in those gases.
Perhaps there was no room in those gases for particles of
water vapor to penetrate. There were either more particles in
the “heavier” gases or those particles were larger. Using his
own data and the Law of Definite Proportions, he
determined the relative masses of particles for six of the
known elements: hydrogen (the lightest and assigned a mass
of 1), oxygen, nitrogen, carbon, sulfur and phosphorous.
Dalton explained his findings by stating the principles of the
first atomic theory of matter.

1. Elements are composed of extremely small particles called atoms.

2. Atoms of the same element are identical in size, mass and other properties. Atoms of
different elements have different properties.
3. Atoms cannot be created, subdivided or destroyed.
4. Atoms of different elements combine in simple whole number ratios to form
chemical compounds.
5. In chemical reactions atoms are combined, separated or rearranged to form new
compounds.
Dmitri Mendeleev (1834-1907) was a Russian chemist known
for developing the first Periodic Table of the Elements. He listed
the 63 known elements and their properties on cards. When he
arranged the elements in order of increasing atomic mass, he
could group elements with similar properties. With a few
exceptions, every seventh element had similar properties (The
eighth chemical group — the Noble Gases — had not been
discovered yet). Mendeleev realized that if he left spaces for the
places where no known element fit into the pattern that it was
even more exact. Using the blank spaces in his table, he was
able to predict the properties of elements that had yet to be
discovered. Mendeleev’s original table has been updated to
include the 92 naturally occurring elements and 26 synthesized elements.

Describing the atom

In 1896, Henri Becquerel discovered radiation. Along with Pierre and
Marie Curie, he showed that certain elements emit energy at fixed rates.
In 1903, Becquerel shared a Nobel Prize with the Curies for the discovery
of radioactivity. In 1900, Max Planck discovered that energy must be
emitted in discreet units that he called “quanta” (since named photons) not
in continuous waves. It appeared that atoms were made up of still smaller
particles, some of which could move away.
In 1911, Ernst Rutherford demonstrated
that atoms consisted of a tiny dense
positively charged region surrounded by relatively large areas of
empty space in which still smaller, negatively charged particles
(electrons) move. Rutherford assumed that the electrons orbit the
nucleus in separate neat orbits, just as the planets orbit the sun.
However, because the nucleus is larger and denser than the
electrons, he could not explain why the electrons were not simply
pulled into the nucleus thus destroying the atom.
Niels Bohr’s (1885-1962) atomic model solved this problem by using
Planck’s information. Photons are emitted from an electrically
stimulated atom only at certain frequencies. He hypothesized that
electrons inhabit distinct energy levels and light is only emitted when
an electrically “excited” electron is forced to change energy levels.
Electrons in the first energy level, closest to the nucleus, are tightly
bound to the nucleus and have relatively low energy. In levels more
distant from the nucleus the electrons have increasing energy.
Electrons in the energy level furthest from the nucleus are not bound
as tightly and are the electrons involved when atoms bond together to form compounds. The
periodic nature of the elemental properties is a result of the number of electrons in the outer
energy level that can be involved in chemical bonds. Although Bohr models have been replaced
by more accurate atomic models, the underlying principles are sound and Bohr models are still
used as simplified diagrams to show chemical bonding.
Our understanding of the atom has continued to be refined. In 1935, James Chadwick was
awarded the Nobel Prize for his discovery that there are an equal number of electrically neutral
particles in the nucleus of an atom. Since neutrons are electrically neutral, they are not deflected
by either electrons or protons. Furthermore, neutrons have more mass than protons. These facts
combine to make it possible for neutrons to penetrate atoms and break apart the nucleus,
releasing vast amounts of energy. In recent years, it is increasingly obvious that the protons,
neutrons and electrons of classical chemistry are made up of still smaller subatomic particles.
The sciences of chemistry and physics are becoming increasingly intertwined and theories
overlap and conflict as we continue to probe the materials out of which our universe is made.

Conclusion

The life of modern man cannot be imagined without chemistry. Chemistry occupies a central
place in almost all areas of modern life. It explores ways in which existing substances can
influence the maintenance, preservation and improvement of the quality of the environment.
Chemistry also plays an important role in designing ways in which existing resources can be
used to enable present and future generations to meet their needs and improve their quality of life
("sustainable development"). Chemistry as a natural science together with physics, biology and
other natural sciences tries to explain various natural phenomena and processes, and chemists
contribute to the development of medicine, agriculture, industry, pharmacy, astronomy and many
other areas of development and knowledge.

Literature:

BERETTA, M. (1992), The historiography of chemistry in the Eighteenth Century: a Preliminary

survey and bibliography, Ambix, 39 (1), 1-11. CHRISTIE, J.R.R. (1994), Historiography of
chemistry in the Eighteenth century: Herman Boerhaave and William Cullen, Ambix, 41 (1), 4-
19.

Trevor H. Levere, Transforming Matter: A History of Chemistry from Alchemy to the

Buckyball, Johns Hopkins Introductory Studies in the History of Science, 2001.

RUSSELL, C.A. (1988), Rude and Disgraceful Beginnings: A View of History of Chemistry
from the Nineteenth Century, British Journal for the History of Science, 21, 273-294.

https://en.wikipedia.org/wiki/Chemistry

Vuk Stojanović IB