Atomic Structure

Unique presence of electrons, protons and neutrons

Last updated 9/2021

English

What you'll learn

The students will have a clear vision about the Structure of Atom.
The students will be able to differentiate between the absorption spectra and emission spectra.
The students will be able to identify Hydrogen Spectra,
The learners will know about Aufbau Principle, Hund's rule of Maximum Multiplicity and Electronic Configuration of Elements.

1 section • 11 lectures • 3h 26m total length

Contents8:53
Discovery of Electron -Cathode Rays24:23
Explore the discovery of the electron through cathode ray experiments, revealing that cathode rays are negatively charged, mass-bearing particles deflected by electric and magnetic fields.
Discovery of proton - positive rays or canal rays19:22
Atomic Models29:34
Atomic Spectrum26:36
Hydrogen Atom16:21
Explore hydrogen atom spectra and energy level transitions, detailing Lyman, Balmer, Paschen, Brackett, Pfund, and Humphreys series observed via discharge tubes and a spectrograph, explained by Bohr and its limitations.
Quantum Numbers22:46
Explore quantum numbers—principal, angular momentum (L), magnetic (M), and spin—defining electron location, orbital shapes (s, p, d), and spin configurations under the Pauli exclusion principle.
Rules for filling of electrons in various orbitals23:34
Dual Nature10:33
Heisenberg’s uncertainty principle11:55
Photoelectric Effect12:30

An atom is electrically neutral, and if it contains negatively charged electrons it must also contain

some positively charged particles, and the supposition that they existed within atoms came about

as a result of Rutherford's experiments in which he bombarded elements with the alpha - rays and

alpha - rays were given off by radioactive elements. The neutron was discovered in 1932 by James

Chadwick by bombarding beryllium with alpha rays.

The electron and proton have equal, but opposite, electric charges; the neutron is not charged.

The existence of electrons in atoms was first suggested, by J.J. Thomson, as a result of

experimental work on the conduction of electricity through gases at low pressures, which

produces cathode rays and x-rays, and a study of radioactivity by Becquerel, the Curies and

Rutherford.

Some of the important properties of the cathode rays studied by Sir J.J. Thomson and others are:

Cathode rays come out at right angles to the surface of the cathode and move in straight lines.

Their path is independent on the position of the anode.

They produce phosphorescence on certain salts like ZnS and fluorescence on glass.

They blacken photographic plates.

The rays pass through thin sheet of metals. If the metal sheet is too thick to be penetrated the

rays cast a shadow.

They produce X-ray when they strike a metal.