Question

1. how did j.j. thomsons discovery of the electron change daltons atomic theory?
2. order the following atomic models from earliest to latest:

a. quantum mechanical model
b. plum pudding model
c. nuclear model
d. solid sphere model
e. bohr model

1. compare and contrast:

a. how is the bohr model different from the quantum mechanical model?

Explanation:

Question 3

Dalton's atomic theory stated that atoms are indivisible. Thomson's discovery of the electron showed that atoms have sub - atomic particles. This contradicted Dalton's idea of atoms being the smallest, indivisible units.

• The Solid Sphere Model (Dalton's model) was the earliest, proposing atoms as solid, indivisible spheres.
• The Plum Pudding Model (Thomson's model) came next, with electrons embedded in a positively charged “pudding”.
• The Nuclear Model (Rutherford's model) followed, with a dense nucleus and electrons around it.
• The Bohr Model (Bohr's model) was after that, with electrons in fixed orbits around the nucleus.
• The Quantum Mechanical Model is the most recent, describing electrons in terms of probability clouds.

• Bohr Model:
• Electrons move in fixed, circular orbits around the nucleus.
• Orbits have definite energies (quantized).
• Describes electrons as particles in specific paths.
• Quantum Mechanical Model:
• Describes electrons as probability clouds (orbitals) around the nucleus.
• Uses wave - particle duality and quantum numbers to define electron location.
• Does not have fixed, circular paths like the Bohr model.

Answer:

Thomson's discovery of the electron showed that atoms are not indivisible (as Dalton's theory proposed), but have smaller sub - atomic particles.

Question 4