-
Period: to
Developmnent of the Atomic Model
It took two centuries of theories and research to form the atomic model we have today. -
The First Model
This was the first recorded model of an atom. It was made by a man named John Dalton, who also came up with the atomic theory. His model portrayed an atom as being a solid sphere and was often compared to objects like a marble. However this model of an atom is very inaccurate compared to what we know today. -
Thomson Model
This was the second atomic model recorded in history. I man named J. J. Thomson invented it. In the model it shows a sphere with a positive charge with negatively charged electrons embedded in it.The model has been compared to a muffin with berries spread around in it. -
Nagaoka Model
This was the third atomic model to be formed and it was made by Hantaro Nagaoka. The model involves negatively charged electrons orbiting around the positively charged sphere in the center. Nagaoka's Model has often been compared to the planets orbitting around the sun. -
Rutherford Model
This model was made by Ernest Rutherford. This model proposed that negatively charged electrons randomly orbit around the a positively charged nucleus. -
Bohr Model
This model was invented by Niels Bohr. He was able to determine that the electrons do not just randomly orbit around the nuclues, and that they orbited in specific layers called shells, and that whenever an electron moved from one shell tol the other it would absorb or give off energy. -
Modern Model
In the 1920s a group of scientists formed this model where there is negatively charged cloud formed by the electrons surrounding the positively charged nucleus that makes the location of the negatively charged electrons' exact location undiscernable. -
Chadwick Model
In 1932, James Chadwick discovered a particle called the neutron. The neutron is a atom paritcle that contains no charge, and it was the key to why the atomic mass of an atom wasn't equal to the atomic mass of the protons and electrons.
