Atomic Theory

Front

What did Rutherford discover in his experiment?

Back

Rutherford discovered the nucleus, a tiny but very dense, positively charged portion of the atom that holds most of the atomic mass.

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Who came up with the first atomic theory?

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John Dalton is credited with formulating the first atomic theory, which proposed that matter is made up of indivisible particles called atoms.

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Who was considered as one of the founders of the ancient atomist theory?

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Democritus is considered one of the founders of the ancient atomist theory, proposing that everything is made up of small, indivisible particles called atoms.

Front

What is the nucleus of an atom?

Back

The nucleus is the central part of an atom, containing protons and neutrons, and is responsible for most of the atom's mass.

Front

Who discovered the electron?

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J.J. Thomson discovered the electron through his experiments with cathode rays.

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What are protons?

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Protons are positively charged particles found in the nucleus of an atom.

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What are neutrons?

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Neutrons are neutral particles found in the nucleus of an atom, contributing to its mass but not its charge.

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What is an electron?

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An electron is a negatively charged particle that orbits the nucleus of an atom.

Front

What is atomic mass?

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Atomic mass is the weighted average mass of an atom's isotopes, measured in atomic mass units (amu).

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What is the atomic number?

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The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.