Untitled Essay, Research Paper

Yazan Fahmawi

T3 IBS Chemistry

Ms. Redman

Historical Development of

Atomic Structure

The thought behind the “ atom ” goes back to the Ancient Greek society, where

scientists

believed that all affair was made of smaller, more cardinal atoms called elements.

They called these atoms atoms, intending “ non divisible. ” Then came the

chemists and

physicists of the 16th and 17th centuries who discovered assorted expression of assorted salts

and H2O, therefore detecting the thought of a molecule.Then, in 1766 was born a adult male named John Dalton born in England. He is known as the male parent

of atomic theory because he is the 1 who made it quantitative, intending he discovered

many multitudes of assorted elements and, in relation, discovered the different proportions

which molecules are formed in ( i.e. for every H2O molecule, one atom of O and two

molecules of H are needed ) . He besides discovered the baronial, or inert gases, and their

failure to respond with other substances. In 1869 a Russian chemist, best known for his

development of the periodic jurisprudence of the belongingss of the chemical elements ( which provinces

that elements demo a regular form ( “ cyclicity ” ) when they are arranged

harmonizing to

their atomic multitudes ) , published his first effort to sort the known elements. His name

was Mendeleyev, and he was a celebrated instructor. Because no good text edition in chemical science was

available at the clip, he wrote the two-volume Principles of Chemistry ( 1868-1870 ) , which

subsequently became a authoritative. During the authorship of this book, Mendeleyev tried to sort the

elements harmonizing to their chemical belongingss. In 1871 he published an improved version

of the periodic tabular array, in which he left spreads for elements that were non yet known. His

chart and theories gained acceptance by the scientific universe when three elements he

“ predicted ” & # 8212 ; Ga, Ge, and Sc & # 8212 ; were later

discovered In 1856 another

of import figure in atomic theory was born: Sir Joseph John Thomson. In 1906, after

learning at the University of Cambridge and Trinity University in England, he won the

Nobel Prize in natural philosophies for his work on the conductivity of electricity through gases. He

discovered what an negatron is utilizing cathode beams. An negatron is the smallest atom in

an atom, whose mass is negligible compared to the remainder of the atom, and whose charge is

negative. Though scientists did non cognize it at the clip, negatrons were located in an

negatron cloud revolving around the karyon, or centre of the atom.Another outstanding figure in atomic natural philosophies is a adult male called Ernest Rutherford, born in

1871. He besides was a professor at the University of Cambridge, the University of Manchester

( both of which are in England ) , and at McGill College in Montreal, Canada. His importance

comes after the find of radiation in 1896 by a Gallic scientist named Becquerel.

Rutherford identified the three chief constituents of radiation: alpha, beta, and gamma

atoms. He besides found the alpha atom to be a positively charged He atom. Besides,

Rutherford was the first one to detect the true construction of an atom, it holding a

cardinal, heavy karyon with an negatron cloud environing it. It was Rutherford that,

through experiments such as go throughing alpha atoms through a thin gold foil and observation

some repel, discovered the 2nd component of the atom ( besides the first constituent of the

karyon ) : the proton. The proton has a comparative atomic mass of one and has a positive

charge. Rutherford besides went down in history as the first adult male to unnaturally do a

atomic reaction when, in 1919, he bombarded N gas with radioactive alpha

atoms, which resulted in atoms of an O isotope and protons.

A unit of

radiation, the rutherford, was named in his award. A co-worker of Rutherford & # 8217 ; s at

Cambridge University was a adult male named James Chadwick discovered the 3rd cardinal

atom that makes up the atom: the neutron. This find led instantly to the

find of atomic fission and the atom bomb The neutron has a comparative atomic mass of

one, and has no positive or negative charge ( i.e. it is impersonal ) . It is found in the

karyon of atoms, along with the proton.

Chadwick was one of the first British

scientists to emphasize the development of a possible atom bomb. His name was strongly

associated with the British atomic bomb attempt, particularly during World War II. During the

last two old ages of W.W.II ( 1943-1945 ) Chadwick moved to New Mexico, where he spent much of

his clip researching at the Los Alamos Scientific Laboratory, a site chosen by the US

authorities for atomic arm research. The first atomic bomb was developed here with the

aid of James Chadwick. Chadwick earned the Nobel Prize for natural philosophies in 1935. In the same

epoch of the development of the atom lived a adult male, merely across the North Sea from these three

learned persons, in Denmark. Neils Henrik Bohr, born in 1885, was besides a considerable

adult male when it came to atomic and atomic natural philosophies. He moved to Cambridge University in 1911,

working under J. J. Thomson, but shortly moved to Manchester to work under Rutherford & # 8217 ; s

supervising. He won the Nobel Prize in natural philosophies in 1922 for his theory on atomic construction

( besides known as the Quantum Theory ) , which was published in documents between 1913 and 1915.

He based his work about Rutherford & # 8217 ; s construct of the atom. This theory, that suggests

that electrons merely emit electromagnetic energy when they jump from one quantum degree to

another, contributed enormously to future development of theoretical atomic natural philosophies. His

work helped take to the impression that negatrons exist in shells and that the negatrons in

the outermost shell attest an atom & # 8217 ; s chemical belongingss. He subsequently illustrated that

uranium-235 is the remarkable isotope of U that undergoes atomic fission. The Bohrs

moved to England, and so to the US, where Bohr went to work for the authorities at Los

Alamos, New Mexico, along with James Chadwick, until the first bomb & # 8217 ; s explosion in 1945.

He disapproved complete secretiveness of the atomic bomb, and believed that its effects

would revolutionise the modern universe. He wanted some kinds of international jurisprudence to watch

over the usage of atomic devices. In 1945 Bohr returned to the University of Copenhagen in

Denmark, where he began developing peaceable utilizations for atomic energy, such as power workss

utilizing atomic resources as opposed to fossil fuels such as coal, oil, and natural gases.

Bohr died in Copenhagen on November 18, 1962. In Austria in 1887 a adult male by the name of

Erwin Schr? dinger was born. He became a physicist best known for his mathematical surveies

of the moving ridge mechanics of revolving negatrons. His most celebrated and of import part to

the apprehension of atomic construction is a punctilious and precise mathematical description

of the standing moving ridges revolving negatrons follow. His theory was published in 1926, and

along with a German physicist & # 8217 ; s theory of matrix mechanics, their theories became the

footing of quantum mechanics. Schr? dinger shared the 1933 Nobel Prize in natural philosophies with the

British physicist Paul A. M. Dirac for his part to the development of quantum

mechanics. Through the centuries that have passed, heads have been boggled, countless

inquiries have been answered, and many great heads conceived, nevertheless, there is no uncertainty

that there is still much to detect about the atom, such as sub-atomic, simple

atoms.

A whole new coevals of great scientists is still to come, to research and unlock the

universe & # 8217 ; s secrets.