Atoms

Democratis: concept of atoms there is one and all matter is composed of atoms (400BC)/ Atomic matter

Aristotle: Matter is made out of 5 elements (400BC)/ Elements

John Dalton: Solid sphere model (1803)/ Solid sphere

JJ Thomspon: Electron exists (1903)/ Plum pudding model

Ernest Rutherford: Nucleus, positively charged (1911)/ Nuclear model 

Niels Bohr: Electrons, orbit the nucleus and are negatively charged (1913)/ Planetary 

Schrodinger and Heisenberg: Electrons can’t be pinpointed (1926)/ Quatuam model

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Atomic Theory- All matter is made of matter, the smallest unit of matter, combined to make different things

Atoms are made out of protons neutrons and electrons

Neutrons: no charge

Electrons: negative charge

Protons: positive charge

Atomic number- number of protons in the nucleus

Atomic mass- number of protons + neutrons

Isotope- a variation of the same type of atom.

Valence Electrons- Electrons in the outermost shell

Elements- a bunch of the same kinds of atoms together (elements can be observed)

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Dmitri Mendeleev (Russia 1869): Organized the elements by atomic mass/ predict the missing elements

Thing element cards have:

-atomic number 

- atomic symbol 

-name of the element

-avg. atomic mass

Elements 1-92 (natural)

Elements 93-118 (man-made)

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Metals: Good conductors, malleable, ductile a lot of variety of metals

Non-metals: poor conductors, brittle gases at room temperature, most of the universe is non-metals

Metaloid (semi-metal): Can conduct in certain conditions