Atomic Theory Scientists Flashcards
Democritus
Engaged in thought experiments → Start of the Atomic Theory
Democritus
Proposed idea that all matter is composed of atoms (tiny particles).
John Dalton
“The Father of Modern Atomic Theory”
John Dalton
Inferred proportions of elements
John Dalton
Proposed that Oxygen and Hydrogen are components of water
William Crookes
First to discover electrons but had no explanation for it
J.J Thomson
Discovered the Electron and explained it (found charge and mass)
J.J Thomson
Showed that electrons were part of matter - the structure of the atom had mass
J.J Thomson
“Raisins in Pudding”
Ernest Rutherford
“The Father of the Nuclear Atomic Atom”
Ernest Rutherford
Made improvements to the atomic model in regard to the characteristics of the nucleus and where the mass is found
Ernest Rutherford
Discovered radiations could split into 3 types of beams with magnetic fields
Ernest Rutherford
“The Gold Foil Experiment”
Ernest Rutherford
Identified the Proton
Henri Becquerel
Discovered Radioactivity
Goldstein
Discovered Protons, but did not know what it is
Chadwick
Discovered the Neutron
Newton
Proposed that light was a particle
Huygen
Proposed that light was a wave
James Maxwell
Proposed that light is an electromagnetic wave
Kerchhoff
Pioneered the field of the study of black bodies
Max Plank
Studied “Black Bodies”
Max Plank
Found a formula that treated light as if it was discrete, NOT continuous
(Treated the energy of the light in quantums of energy)
Heinrich Hertz
Discovered the Photoelectric Effect
Albert Einstein
Says light consisted of streams of Planck’s Quanta, and called them Photons
Neils Bohr
Used Spectroscopy to understand spectral lines
Neils Bohr
improvements to the characteristics of the electron
Neils Bohr
Discovered bright line spectra (coloured lines) and absorption spectra (gases that absorb coloured lines) using gas discharge tube
Neils Bohr
Suggested that light in discrete quantums are also only allowed certain energy levels
Neils Bohr
only accurately predicts special line for only hydrogen
Robert Bunsen & Gustav Kirchhofft
Developed Spectroscopy in 1859
Werner Heisenberg
Discovered the Uncertainty Principle
Erwin Schrodinger
Used (devised) the Wave Equation (Wave Mechanics) to determine the probability of finding an atom’s electrons at a particular point within an atom
Lous De Broglie
First Proposed that matter (particles) could have wave-like properties
Antoine Lavoiser
“Father of Modern Chemistry”
Milikan
Eye drop experiment
Aufbau
Principle - Electrons enter orbitals of lowest energy first
Pauli
Principle - No two electrons in the same atom can have the same set of quantum numbers
Hund
Rule - Electrons occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with parallel spin. Then the second electron then adds to each orbital so that their spin is paired and opposite in direction.
Atomos
the point of indivisibility
Transmutation
Changing one substance into another
Electromagnetic Spectrum
The range of frequencies (frequency of waves is continuous)
Quantum
Energy from light in discrete/individual amounts/packets
Photoelectric Effect
Radiation is shone on a metal and results in flowing energy
Spectroscopy
When white light is passed through a prism, it splits into its component colours
Spectral Lines
Occurs when the electron emits a quantum of energy in the form of light equal to the change in energy level
Uncertainty Principle
It is impossible to know both the position and the momentum of an object beyond a certain measure of precision (mathematically proved)
Orbital (Electron Cloud)
Region of space where the electron is most likely to be found
Isoelectronic - Atoms which have the same electron arrangements
