Atomic theory is the scientific theory that matter is composed of particles called atoms. Atomic theory traces its origins to an ancient philosophical tradition known as atomism. According to this idea, if one were to take a lump of matter and cut it into ever smaller pieces, one would eventually reach a point where the pieces could not be further cut into anything smaller. Ancient Greek philosophers called these hypothetical ultimate particles of matter atomos, a word which meant "uncut". In the early 1800s, the scientist John Dalton noticed that chemical substances seemed to combine and break down into other substances by weight in proportions that suggested that each chemical element is ultimately made up of tiny indivisible particles of consistent weight. Shortly after 1850, certain physicists developed the kinetic theory of gases and of heat, which mathematically modelled the behavior of gases by assuming that they were made of particles. In the early 20th century, Albert Einstein and Jean Perrin proved that Brownian motion (the erratic motion of pollen grains in water) is caused by the action of water molecules; this third line of evidence silenced remaining doubts among scientists as to whether atoms and molecules were real. Throughout the nineteenth century, some scientists had cautioned that the evidence for atoms was indirect, and therefore atoms might not actually be real, but only seem to be real. By the early 20th century, scientists had developed fairly detailed and precise models for the structure of matter, which led to more rigorously-defined classifications for the tiny invisible particles that make up ordinary matter. An atom is now defined as the basic particle that composes a chemical element. Around the turn of the 20th century, physicists discovered that the particles that chemists called "atoms" are in fact agglomerations of even smaller particles (subatomic particles), but scientists kept the name out of convention. The term elementary particle is now used to refer to particles that are actually indivisible. (Wikipedia).
The Atom B1 The Quantum Mechanical Picture of the Atom
The quantum mechanical model of the atom.
From playlist Physics - The Atom
The Atom A3 The Bohr Model of the Hydrogen Atom
The Bohr model of the atom.
From playlist Physics - The Atom
Teach Astronomy - Atomic Theory
http://www.teachastronomy.com/ The atomic theory is the basis of modern chemistry. Dalton published his work in 1810. There are a few key ideas. All elements are composed of atoms. Each element has fundamental and unique chemical properties and is composed of atoms, each of which has u
From playlist 04. Chemistry and Physics
The Atom A4 The Bohr Model of the Hydrogen Atom
The Bohr model of the atom.
From playlist Physics - The Atom
The Atom A5 The Bohr Model of the Hydrogen Atom
The Bohr model of the atom.
From playlist Physics - The Atom
The Atom B2 The Quantum Mechanical Picture of the Atom
The quantum mechanical model of the atom.
From playlist Physics - The Atom
The Atom B3 The Quantum Mechanical Picture of the Atom
The quantum mechanical model of the atom.
From playlist Physics - The Atom
Theory and design are explained using plutonium or uranium.
From playlist Top Science
The Atom A1 Rutherford Scattering
The discovery of the nucleus of the atom.
From playlist Physics - The Atom
11. Atoms in External Fields III
MIT 8.421 Atomic and Optical Physics I, Spring 2014 View the complete course: http://ocw.mit.edu/8-421S14 Instructor: Wolfgang Ketterle In this video, the professor reviewed second order perturbation theory and discussed beyond the quadratic Stark effect, field ionization, and atoms in os
From playlist MIT 8.421 Atomic and Optical Physics I, Spring 2014
Lec 26 | MIT 5.112 Principles of Chemical Science, Fall 2005
Molecular Orbital Theory View the complete course: http://ocw.mit.edu/5-112F05 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
From playlist MIT 5.112 Principles of Chemical Science, Fall 2005
Episode 49: The Atom - The Mechanical Universe
Episode 49. The Atom: A history of the atom, from the ancient Greeks to the early 20th century, and a new challenge for the world of physics. “The Mechanical Universe,” is a critically-acclaimed series of 52 thirty-minute videos covering the basic topics of an introductory university phys
From playlist The Mechanical Universe
Dalton’s Atomic Theory | Don't Memorise
What is the Basic Unit of every Matter? Atoms, right? But this fact which seems obvious now wasn't known earlier. Long time back, a legendary Chemist introduced this fact with the help of his theory. It was Dalton's Atomic Theory. Watch this video to get introduced to this amazing theory a
From playlist Chemistry
Science & Technology Q&A for Kids (and others) [Part 10]
Stephen Wolfram hosts a live and unscripted Ask Me Anything about science and technology for all ages. Find the playlist of Q&A's here: https://wolfr.am/youtube-sw-qa Originally livestreamed at: https://twitch.tv/stephen_wolfram Follow us on our official social media channels. Twitter:
From playlist Stephen Wolfram Ask Me Anything About Science & Technology
Quantum simulation of lattice gauge theories - requirements, challenges and methods by Erez Zohar
PROGRAM NONPERTURBATIVE AND NUMERICAL APPROACHES TO QUANTUM GRAVITY, STRING THEORY AND HOLOGRAPHY (HYBRID) ORGANIZERS: David Berenstein (University of California, Santa Barbara, USA), Simon Catterall (Syracuse University, USA), Masanori Hanada (University of Surrey, UK), Anosh Joseph (II
From playlist NUMSTRING 2022
History | History and Philosophy of Astronomy 9.01
Learn about the history and philosophy of astronomy from Professor Impey, a University Distinguished Professor of Astronomy at the University of Arizona, with our Knowing the Universe: History and Philosophy of Astronomy course here on YouTube. This video is part of module 9, Quantum Theor
From playlist History and Philosophy Course Module 9: Quantum Theory
26. Qualitative MO Theory: Hückel
MIT 5.61 Physical Chemistry, Fall 2017 Instructor: Professor Robert Field View the complete course: https://ocw.mit.edu/5-61F17 YouTube Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP62RsEHXe48Imi9-87FzQaJg This lecture explains the Hückel molecular orbital theory, which deter
From playlist MIT 5.61 Physical Chemistry, Fall 2017
Atomic Physics 1: Quantum Numbers
Video 1 on Atomic Physics which sets out the four quantum numbers, the Pauli Exclusion Principle, the order of filling electron shells and the ordering of elements in the Periodic Table.
From playlist Atomic Physics
An Introduction to Quantum Biology - with Philip Ball
What is quantum biology? Philip Ball explains how strange quantum effects take place in the messy world of biology, and how these are behind familiar biological phenomena such as smell, enzymes and bird's migration. Subscribe for regular science videos: http://bit.ly/RiSubscRibe In this g
From playlist Ri Talks