AS Chemistry - OCR - F321

1. Neutron
2. Proton
3. Electron

Nota:

• Must learn these!

1. Molecule - How elements come together to complete their outer shell
2. Ion - An atom with a charge (+/-)
3. Element - Found on the periodic table
4. Mixture - 2 or more substances together which haven't reacted
5. Compound - Same as a mixture but a reaction has taken place
6. Atom - The smallest part of an element that keeps its chemical properties
7. THE RELATIVE ISOTOPIC MASS IS THE MASS OF THE ISOTOPE COMPARED TO 1/12 OF THE MASS OF AN ATOM OF CARBON-12
8. THE FIRST IONISATION ENERGY IS THE ENERGY REQUIRED TO REMOVE ONE ELECTRON FROM EACH ATOM IN 1 MOLE OF GASEOUS ATOMS TO FORM 1 MOLE OF GASEOUS 1+ IONS

1. Molecules = Non-metals
2. + Ions = Metals
3. - Ions = Non-metals
4. Molecular ions = don't follow these rules

   Nota:

   • Must learn these

1. Same number of PROTONS & ELECTRONS
2. Different number of NEUTRONS

1. Nuclear Charge
   1. Larger charge - more energy needed
2. Shielding
   1. More shielding - less energy needed
3. Distance From the Nucleus
   1. Further from the nucleus - less energy needed

1. Reduction and oxidation
   1. Both occur but to different elements
   2. Disproportionation Reaction
      1. Both occur to the SAME element

1. Properties
   1. High melting points
   2. High boiling points
   3. Low densities
   4. Colourless compounds formed
2. Giant metallically bonded (See bonding section)
3. React by losing 2 electrons from their outer shell to the "sea of delocalised electrons"

1. Halogens
   1. Flourine
   2. Chlorine
   3. Bromine
   4. Iodine
   5. Astatine
2. Colours
   1. Cl2(g)
      1. Element - pale yellow
      2. In H2O - pale yellow
      3. In cyclohexane - yellow
   2. Br2(l)
      1. Element - orange
      2. In H2O - orange
      3. In cyclohexane - dark orange
   3. I2(s)
      1. Element - grey
      2. In H2O - red/brown
      3. In cyclohexane - purple
3. If the halogen is more reactive than the halogen in the compound, it will be displaced

1. HCl - Strong acid
2. Ethanoic - Weak acid
3. All contain H+
4. An acid is a PROTON DONOR

1. A base is a PROTON ACCEPTOR
2. Can be:
   1. Metal oxides
   2. Metal hydroxides
      1. Soluble in water
      2. Produce OH-
      3. pH > 7
   3. Metal carbonates
   4. Ammonia
      1. NH3 + H2O -> NH4OH
3. Neutralise acids
4. A SALT FORMS WHEN THE HYDROGEN ATOMS OF AN ACID ARE REPLACED BY METAL IONS OR AMMONIUM IONS

1. Atoms are ionised
2. + Ions are in a fixed lattice position
3. Outer shell electrons become delocalised
4. Giant metallic bonding
5. Conducts electricity
6. High melting point

1. Simple molecular
   1. Strong covalent bonds - not broken
   2. Weak IMFs
   3. Low melting point
   4. Low boiling point
   5. Do not conduct electricity
2. Giant covalent molecular
   1. Strong covalent bonds - broken
   2. Found only in:
      1. Carbon - Graphite
      2. Carbon - Diamond
      3. Silicon
   3. High melting point
   4. Graphite - conducts electricity
   5. Diamond - does not conduct electricity

1. Electrostatic attraction between oppositely charged ions
2. Giant lattice structure
3. Conduct electricity when molten or dissolved in water
4. Doesn't conduct when solid
5. High melting point