Question

(7:10)
what key limitation did rutherfords model have?
it couldnt explain why electrons didnt collapse into the nucleus.
it didnt include protons.
it ignored the existence of neutrons.
it didnt account for positive charge.
option 5
(7:40)
what did niels bohr propose about electrons?
they exist only in random clouds.
they orbit the nucleus in fixed energy levels.
they can exist anywhere around the atom.
they are part of the nucleus.

Explanation:

• For the first question: Rutherford's model described electrons orbiting the nucleus. But according to classical physics, orbiting electrons (accelerating charged particles) should emit electromagnetic radiation and lose energy, eventually collapsing into the nucleus. Rutherford's model couldn't explain why this didn't happen.
• For the second question: Bohr's model proposed that electrons orbit the nucleus in fixed energy levels (quantized orbits). Electrons can jump between these levels by absorbing or emitting energy.

Answer:

• First question: It couldn't explain why electrons didn't collapse into the nucleus.
• Second question: They orbit the nucleus in fixed energy levels.