Atomic Theory History

What is the main postulate of Dalton's atomic theory?

• All matter is composed of indivisible particles called atoms.

• Atoms are the smallest particles in the universe

• All matter is composed of molecules

• Atoms are continuously divisible

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Who proposed the plum pudding model of the atom?

• J.J. Thomson

• Ernest Rutherford

• Marie Curie

• Niels Bohr

What did Thomson's plum pudding model suggest about the atom?

• The atom is a solid sphere with no internal structure.

• The atom is a negatively charged sphere with positively charged electrons embedded throughout.

• The atom is a positively charged sphere with negatively charged electrons embedded throughout.

• The atom is composed of only positively charged particles.

Which subatomic particle did Rutherford's gold foil experiment discover?

• Electron cloud

• Atomic nucleus

• Proton

• Neutron

In Bohr's model of the atom, what is the significance of the electron's energy levels?

• The electron's energy levels determine the size of the nucleus.

• The electron's energy levels are continuous and can take any value.

• The electron's energy levels represent specific, quantized orbits around the nucleus where the electron can exist without emitting energy.

• The electron's energy levels are directly related to the number of protons in the atom.