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Dalton's Billard Ball Model
Dalton proposed that:
- That all elements are made up of non-divisible atoms.
- That atoms from like elements are the same to one another and atoms from different elements will be different.
- That two raw elements put together make a compound. Ex. H2O.
- That atoms from two different elements can't be changed from chemical reaction.
He experimented with gases to make his assumptions listed above. -
Thomson's Plum Pudding Model
Thomson thought of his model as plum pudding, that the atom was made up of positive liquid which is the pudding. Scattered inside of the atom was electrons, which is the plum in the pudding. He suggested that the electric force between the positive "pudding" and negative "plums" kept the atom together. In 1897, he discovered the electron, which is 2,000 times lighter than a hydrogen atom. -
Rutherford's Planetary Model
He figured that atoms were made up of a small center filled with protons, he called it the nucleus. Rutherford also said the electrons were scattered throught out the empty space of the atom and and moved in orbits, like the planets moving around the sun. Rutherford discovered and named the "proton" in 1917. -
Bohr's Model
The Bohr model is just a modification of the earlier Rutherford model by using the simpiler version of quantum mechanics we use today. He proposed that electrons have certain postions around the nucleus. These are called orbits or shells. He was the first to finalize a model where the electrons are orbiting the nucleus. -
The Quantum Model
Same as the Bohr model, there is a nucleus and rings of energy around the nucleus. The length of each ring was bade on the various energy levels, so the electrons don't move in a definite path. The location of an electron can not be found exactly, scientists can base the probable location based on it's energy. This model shows how electrons move randomly in clouds called orbitals. The size of a nucleus is the size of a marble in the middle of a football field.
