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НазваGreatest Discoveries of Chemistry (реферат)
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на тему:

Greatest Discoveries of Chemistry

Pioneering discoveries that became turning points in the history of

Oxygen (1770s)

British educator and philosopher Joseph Priestley (1733 – 1804)
discovered oxygen in experiments, isolated the gas, and described its
function in combustion and respiration. He also invented soda or
carbonated water by dissolving fixed air with water. Unaware of the
significance of his discoveries and because of his stubborn refusal to
abandon the phlogiston theory, he named the new gas “dephlogisticated
air.” However, it would be the French chemist Antoine Lavoisier (1743 –
1794) who gave the gas its present name, and was able to explain the
nature of the element, accurately describing its role in combustion that
totally discredit the phlogiston theory. In addition, Lavoisier
collaborated with others to develop a systematic chemical nomenclature
that facilitates dialogue among chemists and is still very much in use

Atomic Theory (1800s)

John Dalton (1766 – 1844), English chemist and physicist, proposed the
atomic theory, which states that: a.) all elements are made up of tiny
particles called atoms; b.) all atoms of an element are identical; c.)
the atoms of dissimilar elements can be distinguished from one another
by their corresponding relative weights; d.) atoms of an element can be
combined with atoms of another elements to form chemical compounds; and
e.) atoms cannot be created, broken down into smaller particles, nor
destroyed in a chemical process. He also presented a way of associating
invisible atoms with quantifiable amounts such as mass of a mineral or
volume of a gas. Dalton’s theory has undergone modifications through the
centuries, but it has as much significance for the future of the science
as Lavoisier’s oxygen-based chemistry had been.

Molecules are Made Up of Atoms (1810s – )

At a time when the words “atom” and “molecule” were used
interchangeably, Italian scientist Amedeo Avogadro (1776 – 1856)
clarified that atoms combine to form molecules; and proposed his
eponymous principle which asserts that “Equal volumes of ideal gases, at
the same conditions of temperature and pressure, contain equal numbers
of particles or molecules.”

The Electron (1890s)

Through a series of experiments using cathode ray tubes, J. J. Thomson
(1856 – 1940) discovered that cathode rays emitted negative charged
particles, a component that makes up atoms. He called these particles
“corpuscles,” now known as electrons. He proposed that plum pudding
model, in the belief that atoms consisted of an abundance of these
corpuscles teeming in an ocean of positive charged particles; but this
was subsequently proven to be erroneous when Ernest Rutherford (1871 –
1937) developed the orbital theory of the atom and discovered through
his famous gold foil experiment that atomic masses are largely
concentrated in the nucleus surrounded by electrons.

Electrons for Chemical Bonds (1910s – )

On the foundation of Ernest Rutherford’s theories, Danish physicist
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