Chapter 5 Notes | Chemistry 1st Year

“Atomic Structure”

Index:

1. Sub-Atomic Particles of Atom
2. Rutherford’s Model of Atom (Discovery of Nucleus)
3. Plank’s Quantum Theory
4. Bohr’s Model of Atom
5. Spectrum
6. X-Rays And Atomic Number
7. Wave-Particle Nature of Matter (Dual Nature of Matter)
8. Heisenberg’s Uncertainty Principle
9. Electronic Distribution

Key Points:

1. Matter is made up of extremely small particles called atoms.
2. Cathode rays and positive rays were discovered during discharge tube experiment. The properties of cathode rays showed to them to be negatively charged particles called electrons, whereas, the positive rays were found to contain positively charged particles called protons.
3. Neutron was discovered through artificial radioactivity.
4. Electrons, protons and neutrons are regarded as the fundamental particles of an atom.
5. Rutherford discovered the nucleus and successfully explained the presence of moving electrons around the nucleus.
6. In 1905, Plank put forward his famous Plank’s Quantum Theory.
7. Neil Bohr explained the structure of hydrogen atom by using Plank’s quantum theory. He also calculated the radius and energy in the nth shell of hydrogen atom.
8. Bohr’s atomic model successfully explained the origin of line spectrum and the lines present in the spectrum of hydrogen atom in the visible and invisible regions.
9. X-rays are produced when rapidly moving electrons collide with heavy metal anode in the discharge tube.
10. Moseley discovered a simple relationship b/w the frequency of X-rays and the atomic number of the target element.