-
John Dalton is born
Dalton is born in Eaglesfield, UK -
Dalton defines the atom
Dalton hypothesized that the law of conservation of mass and the law of definite proportions could be explained using the idea of atoms. He proposed that all matter is made of tiny indivisible particles called atoms, which he imagined as "solid, massy, hard, impenetrable, movable particles.” -
Robert Millikan is born
Robert Millikan is born in Morrison, USA -
Albert Either is born
Einstein is born in Ulm, Germany -
Niels Bohr is born
Niels Bohr is born in Copenhagen, Denmark. -
Erwin Scheodinger is born
Erwin is born in Vienna, Austria -
James Chadwick is born
James Chadwick is born in Bollington, UK -
Louis De Broglie
Broglie is born in Dieppe, France -
Werner Heisenberg
Heisenberg is born in Würzburg, Germany -
Albert Einstein’s atomic findings
- Mathematically proved the existence of atoms
- Using Planks finding explained the Photoelectric effect, where electrons are ejected when light shines on a metal
- Proposed concept of Photons
-
Robert Millikan determines the magnitude of the electrons charge
He found this by taking 2 electrically charged drops of oil and suspended them between two metal plates where they were subjected to the downward force of gravity and upward attraction of an electrical field -
Neils Bohr’s atom findings
- Neils Bohr creates a new atomic model
- Proposed that an electron is found only in specific circular paths, in orbit, around the nucleus
- Each electron orbit has a fixed energy called energy levels.
- Found this information by studying the way glowing, hot hydrogen gave off light
-
Louis De Broglie describes electrons as waves
- Introduce the idea that particles, such as electrons, could also be described as waves
- He thought this by the way streams of electrons were reflected against crystals and spread through thin metal foils
-
Erwin Schrodinger creates the Quantum Mechanical Model
- Using Bohr's model he created the Quantum Mechanical Model
- Quantum Mechanical Model used these calculations to describe the behavior of electrons
- He made this by combining the equations for the behavior of waves with the de Broglie equation.
-
Werner Heisenberg concludes uncertainty
He discovered that a particle’s position and momentum can’t be known exactly -
James Chadwick proves the existence of Neutrons
- Proved the existence of neutrons
- He conducted an experiment where he bombarded Beryllium with alpha particles from the natural radioactive decay of Polonium.