C1
- Created by: ak27330
- Created on: 03-11-19 14:40
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- C1
- History of the Atom
- The plum pudding model
- Dalton described atoms as solid spheres.
- Different spheres, different elements.
- A ball of positive charge with electrons stuck in it
- Rutherford's nuclear model
- Gold foil experiment
- Fire positively charged alpha particles at thin sheet of gold.
- Expecting- to pass through. Some were deflected.
- Fire positively charged alpha particles at thin sheet of gold.
- tiny positive nucleus at centre, 'cloud' of negative electrons, mostly empty space.
- Gold foil experiment
- Bohr's nuclear model
- Rutherford's model- would cause atom to collapse.
- Electrons orbit the nucleus at fixed distances.
- The discovery of protons and neutrons
- Discovered late 1920's
- The plum pudding model
- The Atom
- protons- +1 charge, neutron- 0 charge, electron- -1 charge
- Mass- proton=1, neutron=1, electrons= negligible
- proton, neutron in nucleus, electrons on shell
- Isotopes and Relative Atomic Mass
- Isotopes- same number of protons, different number of neutrons
- Relative Atomic mass- average mass of an atom
- RAM= (sum of(isotope abundance X isotope mass number)) / sum of abundances
- Development of the Periodic Table
- Mendeleev- order of atomic mass
- Left gaps so certain elements can be in certain groups due to chemical properties
- Mendeleev- order of atomic mass
- The Modern Periodic Table
- Sorted via atomic number, vertical= similar chemical properties
- Period number= shells
- Electronic configuration
- shells= 2.8.8.
- Group 0= full shell, noble gases
- Ions
- Charged particles- either lose or gain electrons
- Cation- positive
- Anions- negative
- Ionic Bonding
- Bond between non-metals and metals
- Ionic Compounds
- Strong electrostatic forces between oppositely charged ions
- Properties
- High melting and boiling point, to overcome strong electrostatic attraction
- High solubility
- Electrical conductivity- doesn't conduct electricity, does when melted or dissolved as ions are free to move and carry a charge
- Covalent Bonding
- Between non-metals where they share electrons, by electrostatic forces
- Simple molecular substances
- Tiny, atoms joined by covalent bonds
- Properties
- No electrical conductivity
- low melting and boiling points
- Polymers- long chains of covalntly bonded carbon
- Giant Covalent Structures
- Strong covalent bonds, high melting points and boiling points, aren't soluble
- Diamond- four covalent bonds, rigid, high melting points, doesn't conduct.
- Graphite- three covalent bonds, sheets of graphene, held w/ weak intermolecular forces, soft/slippery, conductor, high melting.
- Fullerenes used in medicine, catalysts and strengthening materials.
- Metallic Bonding
- Giant structure, delocalised electrons, conduct electricity
- High melting and boiling points, high conductivity, malleable, dense.
- Relative Mass
- Relative formula mass= masses of atoms in compound added together.
- Empirical formula= simplest whole number ratio of atoms of each element within a compound.
- Molecular formula- empirical formula of a compound with the RFM to work out how it was originally.
- No atoms can be destroyed or created.
- Learn empirical formula separately.
- Concentration(g dm-3)= mass of solute(g) / volume of solution(dm3)
- The mole
- Avogadro constant= 6.02 X 10^23
- How many particles there are
- Num of moles= mass(g) / RAM or RFM
- Mass of product w/ balanced equation
- If you know the mass of a product and have a balanced equation you can work out the other substances with it.
- Limiting reactants- when a reactant is used up before reaction can finish.
- If you know the mass of a product and have a balanced equation you can work out the other substances with it.
- History of the Atom
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