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chemistry - C1 - Coggle Diagram
chemistry - C1
THE ATOM
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tHE NUCLEUS - contains protons and neutrons, pos charge and is almost the whole mass of the atom.
molecule - when atoms bond, can be the same element, simple molecules are tiny. nanoparticles - bit bigger
ATOMS, IONS, ISOTOPES
Atomic number - number of protons, atoms of the same element have the same number.
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mass number - bigger number, total number of protons and neutrons
ions - formed when atoms gain or lose electrons. Neg ions - gain electrons as they have more electrons than protons, pos when lose electrons as more protons that neutrons
Isotope - different forms of same element, same protons, different neutrons eg carbon
MATTER
SOLID - strong forces of attraction, regular lattice, keep shape, vibrate
Liquid - some force of attraction, free to move, no definite shape, constantly moving, constant volume
GAS - no force of attraction, free to move, travel in straight lines, no definite shape or volume, they exert pressure on wall
When a substance changes state it is a physical change so no new substances are made. During reaction, bonds break, and the atoms rearrange themselves. easy to reverse
History
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Rutherford - gold foil experiment - fired pos alpha particles at sheet of gold. deflected back so came up with the nuclear atom, where the centre was pos surrounded by a cloud of neg
Bohr - identified that the 'cloud' of electrons would make it collapse so came up with the shells idea. Suggested they can only exist in a fixed orbit with fixed energy. supported by many experiments