Question 5
Explain and arrange the following statements in the correct chronological order to show how atomic models have evolved over time. (i) Bohr’s model proposed that electrons move in fixed orbits around the nucleus, each with a definite energy. (ii) Thomson’s model depicted the atom as a ‘plum pudding’ with electrons embedded in a sphere of positive charge. (iii) Rutherford’s model proposed that atoms have a dense central nucleus. (iv) Dalton’s model described atoms as indivisible particles.
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  • 1. Dalton (iv) — atoms are indivisible particles.
  • 2. Thomson (ii) — plum-pudding: electrons embedded in a positive sphere.
  • 3. Rutherford (iii) — atom has a dense central nucleus.
  • 4. Bohr (i) — electrons move in fixed orbits of definite energy.

Order: (iv) → (ii) → (iii) → (i) .

Order of Atomic Models
1. Dalton: indivisible atom 2. Thomson: plum pudding 3. Rutherford: nuclear model 4. Bohr: fixed energy levels
Back to: 8.2 A Short Historical Journey Through Atomic Models
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