- Created by: georgiemountford
- Created on: 22-09-19 20:12
ATOMIC MODELS OVER TIME -
- Dalton's atomic theory: Atoms are indivisible. All atoms of one element are the same, and different from atoms of another element.
- Thomson's plum-pudding model: Discovers electrons (negative charge, tiny mass). Disproved Dalton's theory - atoms can be split further. Model: Electrons in a 'sea' of positive charge. Atom overall is neutral.
- Rutherford's nuclear model: Alpha scattering experiment showed that atoms are mostly empty space, with their mass concentrated in their positive nucleus (at the centre of the atom). Electrons orbit the nucleus.
- Bohr's planetary model: Electrons orbit the nucleus in shells.
- Discovery of protons (Rutherford) and neutrons (Chadwick) in the nucleus.
ATOMIC MASSES -
- Relative atomic mass: Weighed mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12.
- Relative isotopic mass: Mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12.
AMOUNT OF SUBSTANCE -
- Avogadro constant: Number of atoms per mole (12g) of carbon-12.
- Molar mass: Grams per mole of a substance.
TYPES OF FORMULAE -
- Empirical formula: Simplest whole-number ratio of atoms of each element in a compound.
- Molecular formula: Number of atoms of each element in a molecule.
- Water of…