Question

Gina summarizes the ideas that led to the current atomic model.
1. Dalton developed the theory that all matter is made of atoms.
2. Thomson discovered that atoms contain electrons.
3. Rutherford discovered that atoms have a nucleus.
4. Schrödinger developed the electron cloud model.
5. Bohr developed the model in which electrons orbit the nucleus.

Which change should Gina apply to correct the summary?
Switch 1 and 5.
Switch 2 and 3.
Switch 4 and 5.
Switch 3 and 1.

Answer 1

Switch 4 and 5.

Bohr (1913) proposed electrons in quantized orbits before Schrödinger (1926) developed the electron cloud/wave-mechanical model.