Flashcard - Atomic Theory

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What is Dalton's atomic theory?

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Dalton's atomic theory states that all matter is made up of atoms, which are indivisible and indestructible particles. Atoms of a given element are identical in mass and properties, and compounds are formed by the combination of different types of atoms.

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What subatomic particle did J.J. Thomson discover?

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J.J. Thomson discovered the electron, which is a negatively charged subatomic particle.

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How did Thomson's model of the atom differ from Dalton's model?

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Thomson's model proposed that atoms are not indivisible but consist of smaller particles (electrons) embedded in a positively charged 'soup', unlike Dalton's model which viewed atoms as solid, indivisible spheres.

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What did J.J. Thomson's model suggest about the structure of the atom?

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Thomson's model suggested that atoms are uniformly packed spheres of positive matter filled with negatively charged electrons.

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What was the main conclusion of Rutherford's gold foil experiment?

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Rutherford's gold foil experiment concluded that atoms consist largely of empty space with a dense, positively charged nucleus at the center.

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What did Rutherford's experiment reveal about the nucleus?

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Rutherford's experiment revealed that the nucleus is small, dense, and positively charged, containing most of the atom's mass.

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What is the significance of the Bohr model of the atom?

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The Bohr model introduced the idea that electrons move in fixed orbits around the nucleus, with specific energy levels, which explains the quantized nature of atomic energy.

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Who proposed that electrons move in definite orbits around the nucleus?

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Niels Bohr proposed that electrons move in definite orbits around the nucleus.

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What is the concept of atomic mass?

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Atomic mass is the weighted average mass of an atom's isotopes, measured in atomic mass units (amu), reflecting the number of protons and neutrons in the nucleus.

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What is the difference between an atom and a molecule?

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An atom is the smallest unit of an element, while a molecule is a group of two or more atoms bonded together, representing the smallest unit of a chemical compound.