Atomic Structure

Unique presence of electrons, protons and neutrons

Created byVinay Arya

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.

Course content

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

Contents8:53
Explore the structure of atoms, from electrons and protons to atomic models and spectra. Learn the discovery of electrons and protons, plus quantum numbers and the photoelectric effect.
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
Goldstein's 1886 canal rays revealed positively charged particles, protons with charge equal to electron charge and mass near hydrogen. Chadwick's 1932 beryllium-alpha experiments yielded neutrons, particles with mass near protons.
Atomic Models29:34
Trace the evolution of atomic models from Thomson's plum pudding to Rutherford's nucleus, illustrated by the gold foil experiment, electron orbit ideas, and Bohr's refinements.
Atomic Spectrum26:36
Explore emission and absorption spectra, energy levels, and the hydrogen atom through Bohr's model, showing how photon transitions reveal line spectra and ionization energies.
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
Explain how electrons fill orbitals using the Aufbau principle, Hund's rule of maximum multiplicity, and the Pauli exclusion principle to determine electronic configuration.
Dual Nature10:33
Demonstrates the dual nature of light and electrons, linking wave and particle behaviors with de Broglie wavelength and Einstein's relation, and explains diffraction, interference, and photon-based phenomena.
Heisenberg’s uncertainty principle11:55
Explore Heisenberg’s uncertainty principle, linking position and momentum uncertainties, and learn how Schrödinger’s equation and the wave function describe the three-dimensional motion of electrons in atoms.
Photoelectric Effect12:30
Explore the photoelectric effect, where light ejects electrons from a metal surface, with kinetic energy linked to photon energy and light frequency, and stopping potential and threshold frequency concepts.

Requirements

The learner should be aware of Elements, compounds and mixtures.

Description

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.

Who this course is for:

Biggane and eleventh standard students.