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ATOMS - Coggle Diagram
ATOMS
Structures of Atoms
Atomic Mass
The average mass of an atom, taking into account all its naturally occurring isotopes.
Proton
Positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element. It weighs 1 amu.
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Neutron
A subatomic particle forming part of the nucleus of an atom. It has no charge. It is equal in mass to a proton or it weighs 1 amu.
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Early Concepts
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The Greek philosopher Democritus was the first person that theorized that matter was made of small, indivisible (Greek: atomos) parts.
The first model of the atom (“soccer ball”) was introduced by John Dalton in early 1800. He thought of the atom as a featureless ball of uniform density.
Dalton’s model was refined by J.J. Thomson, who discovered the electron and the charged nature of the atom.
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The nuclear model describes the atom as having a dense positively charged center (nucleus) surrounded by negatively charged particles (electrons).
Development
Bohr Model
The Bohr model depends on a connection between the frequency of light and the energy of the level change. Electrons are small and negatively charged. For a particular element, only certain frequencies (colors) of light are absorbed or emitted.
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Schrodinger Model
Schrodinger discovered that electrons don't move in orbits (or in a set path at all). He theorizes electrons move in waves, and they have no exact location.
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Dalton's Model
He just expanded on the Greek idea of the atom. An atom is a small things, and there are different masses with different properties. Stuff can be broken into elements (the things listed on the periodic table).
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Rutherford Scattering
Rutherford's experiment prompted a change in the atomic model. If the positive alpha particles mostly passed through the foil, but some bounced back. Rutherford found that most of them went right through the foil.
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Gold-foil experiment showed that the atom consists of a small, massive, positively charged nucleus with the negatively charged electrons being at a great distance from the centre
The smallest possible amount of matter which still retains its identity as a chemical element, consisting of a nucleus surrounded by electrons.
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