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Dalton's Theory
All matter is made of atoms.
Atoms are indivisible and indestructible.
All atoms of an element are identical in mass and properties.
Compounds are formed by 2 or more kinds of atoms.
Chemical reaction = rearrangement of atoms -
JJ Thomson's Theory
An atom consists of a sphere of positive charge with negative charged electrons stuck in it.
The positive and negative charges are equal in magnitude, making it nor an overall negative or positive charge. (It is electrically Neutral). -
Rutherford's Theory
Rutherford described the atom as a tiny, dense and positive charged nucleus in which all mass is concentrated.
Around this nucleus, electrons revolve around like planets do. -
Bohr's Theory
Bohr depicts the atom just as Rutherford with a nucleus and electrons floating around, but instead of gravity sustaining the electrons, he sustains attraction is provided by electrostatic forces.
The number of electrons that orbit around the atomic nucleus increases from the inside to the outside. -
Schroedinger & Heisenberg's Theory
Schroedinger showed through maths that waves can be used to describe electrons in atoms and built the Electron Cloud Model that depicts the floating motion of electrons, introducing Heisenbergs uncertainty principle, claiming that you can't know the exact position of a particle due to uncertainty in the momentum getting larger.
