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Period: to
Models of the Atom
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Dalton's Billiard Ball Model
Dalton concluded that all matter is made up of atoms, and that each element has its own kind of atom. He thought that atoms from the same element have the same mass, and atoms from different elements have different mass. He found that atoms don't get destroyed during chemical reactions, they just get moved around. -
Thomson's Plum Pudding Model
Thomson found out that atoms have particles called electrons inside of them. He had discovered the electron in 1897. Electrons have a small mass and a negative charge, and the rest of the model is a sphere of positive charge. He thought that the electrons were embedded in the sphere, thus making the atoms neutral. -
Rutherford's Solar System Model
Rutherford overturned Thomson's model in 1911 with the gold foil experiment. He discovered that an atom consists mostly of empty space. He thought it had a dense postively charged nucleus that is surrounded by electrons. -
Bohr's Model
This model looked like a solar system. He believed the atom consisted of a small, postive nucleus surrounded by electrons that moved in orbit. The way it was structured looked a lot like a solar system. Bohr was actually a student of Rutherford's, that's why this model is so much like the solar system model. -
Quantum Model
There were many people who helped form the Quantum theory . They discovered that an atom is made up of a dense nucleus that has both protons and neutrons in it. They also found out that electrons don't move around the nucleus like the planets around the sun. This model shows that they move randomly in clouds called orbitals. They found out that it's impossible to know the exact location of an electron, but the probable location is based on its energy.
