Atomic Theory - Introduction

Atomic Theory is the theoretical understanding regarding the fundamental unit of all matter, that is the atom. The phrase atom' is derived from the atom structure which means indivisible. From the age of Greek Philosophers like Democritus and Aristotle, it had been believed and proposed that every reason should be broken below until the tiniest unit is reached. It was only during the late eighteenth 100 years that Atomic Theory started to emerge. Dalton's Atomic Theory:.

English Scientist Paul Dalton was first to propose his atomic theory in 1808. His theory consisted of 5 postulates:. Every element is composed of atoms. All the atoms in an element have the similar to structure. Atoms cannot be divided, shall be neither created nor destroyed.

Atoms of different elements shape compounds. All chemical reactions involve combination, separation or rearrangement of atoms. Later scientific studies disproved little of Dalton's postulates, particularly the discovery of nucleus and electrons dispelled the notion that atom cannot be divided further. This lead to development of Atomic models which described the structure of an atom. It was only during early twentieth 100 years that the greatest accurate model of an atom was established.

Prior to that many scientists hypothesized the structure of an atom, of which the greatest notable ones are. Thomson's Plum-pudding model, which describes atom as possessing negatively charged electrons embedded within positively charged fabric similar to plums in a pudding. New Zealand Scientist Ernest Rutherford's model that describes atom as possessing a tiny nucleus at the center surrounded by electrons which circle around it. Danish Physicist Neil Bohr's planetary model, a development over Rutherford model, which proposes that electrons revolve around the nucleus in fixed orbits at different life levels, and they can jump between the orbits. An atom is stable when the electrons are in their lowest life states.

Quantum model or Cloud model that greatest explains atomic behavior. It explains that instead of fixed orbits, electrons exist like clouds and are located anywhere around the nucleus in regions called orbitals. The arrangement of electrons within the orbitals electron configuration regarding the atom is described by a set of quantum numbers. They represent the life position regarding the electrons and are unique for each electron. With numerous scientific experiments, different subatomic particles were discovered beyond the protons, neutrons and electrons.

Little of them are positrons, quarks, bosons, neutrinos etc. and new ones are still being discovered. Hence the atomic models hold expanding. Atom Characteristics:. many protons within the nucleus.

The many electrons equal the protons in a neutral atom. Atomic mass sum regarding the weights of protons and neutrons within the nucleus. Electrons and other subatomic particles are too miniscule to attribute to weight. These are the greatest important characteristics of any atom.