-
John Dalton-Atomic Theory
1) All matter is made of atoms. Atoms are indivisible and indestructible. 2) All atoms of a given element are identical in mass and properties 3) Compounds are formed by a combination of two or more different kinds of atoms. 4) A chemical reaction is a rearrangement of atoms. -
Dalton´s Model
Where Dalton advanced atomic theory was by saying we had many different atoms out there. His model, often dubbed the "billiard ball" model, basically says you can't divide the atom into smaller pieces.
All matter is made up of atoms, and these little guys are indivisible (can't break them apart) and indestructible (can't break them down). -
William Crookes
Was a British chemist and physicist who attended the Royal College of Chemistry, London, and worked on spectroscopy. He was a pioneer of vacuum tubes, inventing the Crookes tube. Crookes was the inventor of the Crookes radiometer which today is made and sold as a novelty item. -
J.J. Thomson
Was a British physicist that showed that cathode rays were composed of a previously unknown negatively charged particle, and thus is credited with the discovery and identification of the electron. -
J.J. Thompson´s Model
The plum pudding model of the atom by J. J. Thomson, consisted of an atom which is composed of electrons surrounded by a soup (or cloud) of positive charge to balance the electrons' negative charges, like negatively charged "plums" surrounded by positively charged "pudding". The electrons (as we know them today) were thought to be positioned throughout the atom, but with many structures possible for positioning multiple electrons, particularly rotating rings of electrons. -
Rutherford Model
Rutherford's model for the atom, based on the experimental results, contained the new features of a relatively high central charge concentrated into a very small volume in comparison to the rest of the atom and with this central volume also containing the bulk of the atomic mass of the atom. This region would be named the "nucleus" of the atom in later years. -
Bohr Model
In atomic physics, the Bohr model, introduced by Niels Bohr in 1913, depicts the atom as small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar in structure to the solar system, but with attraction provided by electrostatic forces rather than gravity. -
Ernest Rutherford
Was a New Zealand-born physicist and chemist who became known as the father of nuclear physics. The gold foil experiment involved the firing of radioactive particles through minutely thin metal foils (gold) and detecting them using screens coated with zinc sulfide (a scintillator). Rutherford found that although the vast majority of particles passed straight through the foil approximately 1 in 8000 were deflected leading him to his theory that most of the atom was made up of 'empty space'. -
Quantum Mechanical Model
The quantum mechanical model is based on quantum theory, which says matter also has properties associated with waves. According to quantum theory, it’s impossible to know the exact position and momentum of an electron at the same time. This is known as the Uncertainty Principle.The quantum mechanical model of the atom uses complex shapes of orbitals, volumes of space in which there is likely to be an electron. So, this model is based on probability rather than certainty. -
Niels Bohr
Was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. -
James Chadwick
English physicist who was awarded the 1935 Nobel Prize in physics for his discovery of the neutron in 1932.
