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Dalton's atomic theory remains valid in modern chemical thought. 1)All matter is made of atoms. Atoms are indivisible and indestructible. 2) Compounds are formed by a combination of two or more different kinds of atoms.

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Rutherford overturned Thomson's model in 1911 with his well-known gold foil experiment in which he demonstrated that theatom has a tiny, heavy nucleus. Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure.

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Who was the first person known to have developed a valid theory of atomic structure?

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Who was the first person known to have developed a valid theory of atomic structure?

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Democritus first suggested the existence of the atom but it took almost two millennia before the atom was placed on a solid foothold as a fundamental chemical object byJohn Dalton (1766-1844).

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An atom is a particle of matter that uniquely defines a chemical element. An atom consists of a central nucleus that is usually surrounded by one or more electrons. Each electron is negatively charged. The nucleus is positively charged, and contains one or more relatively heavy particles known as protons and neutrons.

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The radius of a typical atom is one tenth of a billionth of a meter. A string of atoms one meter (about 3 ft) long contains an atom for every person in the world. A cube of sugar contains as many atoms as there are stars in the Universe.

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What is Aristotle's idea on the structure of an atom?

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What is Aristotle's idea on the structure of an atom?

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Aristotle (384-322 BC) was a proponent of the continuum. He believed in the four elements of air, earth, water and fire. Aristotle felt that regardless of the number of times you cut a form of matter in half, you would always have a smaller piece of that matter.