Italics Topics are Triple Science ONLY
, Chapter 1 – Separating Techniques
Filtration Crystallisation Chromatography Simple Distillation
- Used to separate - Used to obtain solid - Used to separate - Used to separate 2 mixtures
- insoluble substance - crystals from a - pigments of soluble- The mixtures are heated first and gas
- from a liquid. - solution. - dyes - is produced
- The gas goes into a condenser and
- A circle of filter - The solution is - Stationary Phase: the - then it will condense into a liquid.
- paper is folded to - heated to let some of - phase that doesn’t
- make a cone and - solvent evaporate. - move e.g. the paper Fractional Distillation
- placed into a filter - Used to separate mixtures with
- funnel. - Heating should be - Mobile Phase: - different boiling points
- stopped when small - solvent moves - Example: Crude Oil Separation
- Gravity pulls down - crystals form. - through the paper
- the liquid and solid - carrying different Crude oil is extracted from underground, it is a
- particles which are - The rest is left to - substances fossil fuel so non-renewable.
- caught by the filter - evaporate at room It is heated up and gas travels into a fractionating
- paper. - temp to get a good - Example: Drug Tests column which has a temp gradient from hot to
- sample of crystals. cold.
- Example: mixture of Rf Value = distance
pigment / distance Different compounds from the mixture of crude oil
- sand or salt, NaCl - Example: salt from turn into their condensed state at their boiling
solvent travelled
- and water - seawater points.
, Chapter 1 – Atomic Structure
- Molecule: chemically History of the Atom
- bonded atoms 1) John Dalton – Atom is a plain sphere that makes up everything
- Compound: 2) JJ Thomson – Created the plum pudding model, the whole sphere being positive and
- chemically bonded 2 2) with randomly scattered – charge electrons
- or more different 3) Rutherford – Discovered the concentrated part of positive in the middle. This was
- element atoms 3) from the gold foil experiment
4) Niels Bohr – Discovered shells and that electrons weren’t randomly scattered.
- Mixture: 2 or more 5) James Chadwick – Discovered neutrons and the model we have today
- atoms
Gold Foil Experiment
- Ions: atoms with a
- The experiment was carried out by Geiger & Marsden.
- charge
- Atoms don’t have an Experiment:
- overall charge as the - They shot alpha ray particles at a piece of gold foil.
- + and – subatomic - They expected for the alpha rays to shoot straight
- particles are equal - through the foil at a 180 degrees angle.
- Isotopes: atoms with Observations:
- the same number of - Some rays went straight through, showing that most of the atom was empty space.
- protons but different -- - Many rays deflected back at large and small angles thus showing that the atom had a
- number of neutrons. - dense positive nucleus in the middle.
, Chapter 2 – The Periodic Table
Group 1 (Alkali Metals)
Reactivity:
Observations when reacting with water
- Vigorous reactions with water
- Forms metal oxides Floats, gentle fizzing, gradually dissolves to
Li
- Forms ionic compounds (with G7) give a colourless solution.
- Reactivity increases going down Floats, vigorous fizzing, melts & Na rapidly
o Outer electron needs to be lost Na
dissolves to give a colourless solution.
o Going down, shells increase
o Electron shielding decreases Floats, very vigorous fizzing, burst of lilac
o Electrons can be lost easily K flame and K very rapidly dissolves to give a
colourless solution.
Properties: Sinks, explosive release of gas, and Rb
- Soft texture Rb instantaneously dissolves to give a
- Relatively low m/b points colourless solution.
- Low Densities
Sinks, violently explosive release of gas,
- M/b points decrease going down
Cs and Cs instantaneously dissolves to give a
o Metallic bonds become weaker
colourless solution.
o Because atoms get larger
o Outer electrons are further away from nucleus
o Attraction between + ions and delocalised electrons is weaker.
, Chapter 2 – The Periodic Table
Group 7 (Halogens)
Reactivity:
- Forms ionic compounds (with Group 1) The more reactive element displaces the less
- Reactivity decreases going down reactive element in a compound for example:
o Outer shell needs to gain an electron
o Going down, shells increase Cl2 + 2NaBr 2NaCl + Br2
o The force of attraction with nucleus Chlorine displaces Bromine as it is more reactive.
gets weaker
o Therefore, it’s harder to gain electrons
Chlorine Bromine Iodine
Properties: Cl2 (aq) Yellow/
Brown
- Exist as a diatomic molecule Orange
Solution
- Don’t conduct electricity Solution
- M/b points increase going down Br2 (aq) No
Brown
o Molecules become larger going down reaction/
Solution
o There are more electrons in each atom change
o Stronger intermolecular forces I2 (aq) No No
between the molecules reaction/ reaction/
o So, more energy is needed to change change
overcome these forces
, Chapter 2 – The Periodic Table
Transition Metals
- Located between groups 2 and 3 on the periodic table
- Large central block in the periodic table
- Creates compounds (salts)
Physical Properties:
- Good Conductors of Heat & Electricity
- Hard and Strong
- High Density and high melting points (except Mercury)
Chemical Properties:
- Multiple Oxidation states
- Therefore, coloured compounds
- e.g. Iron III Chloride
Comparison with Group 1
- Transition Metals are less reactive than Group 1 e.g. they don’t react readily with oxygen, water, and chlorine.
- Transition Metals have high density and high melting points, whereas Group 1 have low density and low mp.
- Transition Metals have to be heated strongly for a reaction to occur:
- 2Cu + O2 2CuO
, Chapter 2 – The Periodic Table
Development
1) John Dalton – He sorted elements in terms of atomic mass.
2) Johann Dobreiner – He sorted elements into threes (triads) as he noticed similar chemical properties.
3) John Newlands – He noticed that every eighth element had similar properties and ordered elements in terms of
3) masses. He called this the Laws Of Octaves. However, he was criticised as elements with different properties
3) were grouped as only atomic mass was looked upon.
4) Mendeleev – He ordered elements considering masses and properties. He is
4) significantly known for leaving gaps in his table as with his calculations, certain
4) elements were missing. He later, predicted properties of undiscovered
4) elements. As well as this, he put Iodine after Tellurium despite Iodine having
4) a higher atomic mass, to ensure that elements with similar properties were
4) grouped together.
5) Later Scientists – They arranged elements by their atomic numbers (protons) and added the noble gases
5) (Group 0). They also proved Mendeleev’s theory by adding in elements where Mendeleev had left gaps.
, Chapter 3 – Bonding, Structure & Matter
Ionic Bonding Covalent Bonding
- Between metals and non-metals - Between two non-metals
- Electrons are transferred - Electrons are shared
- Metals loses electrons ( + charge) - Both atoms share electrons, and charges aren’t gained
- Non-metals gain electrons ( - charge) - or lost
- Both are held together by opposite charges
Examples:
Examples:
Magnesium Oxide (MgO) Sodium Chloride (NaCl) Chlorine Molecule (Cl2) Water (H2O)
Limits of Dot & Cross Comparison of Ionic & Covalent
Diagrams: - Ionic forms lattices whereas covalent can’t as they aren’t ions.
- Cannot see states of matter - Covalent has low melting points whereas Ionic has high mp.
- Cannot see the transfer of electrons - Generally Ionic is solids, and covalent is liquid or gas.
- Cannot see relative sizes - Ionic has strong whereas covalent has weak intermolecular forces.
, Chapter 3 – Giant Covalent Structures
Diamond
Properties
- Hardest natural substance
- No intermolecular forces
- High melting/boiling points
- Doesn’t conduct electricity
- Insoluble in water
- Tetrahedral arrangement
- Transparent and sparkly
- Each carbon atom is bonded
- to 4 others, so no delocalised
- electrons to conduct electricity.
Uses
- Jewellery and Industrial drills
- This is because each carbon
- makes 4 strong covalent bonds
- So, the hardness, makes it
- suitable for its uses.
, Chapter 1 – Separating Techniques
Filtration Crystallisation Chromatography Simple Distillation
- Used to separate - Used to obtain solid - Used to separate - Used to separate 2 mixtures
- insoluble substance - crystals from a - pigments of soluble- The mixtures are heated first and gas
- from a liquid. - solution. - dyes - is produced
- The gas goes into a condenser and
- A circle of filter - The solution is - Stationary Phase: the - then it will condense into a liquid.
- paper is folded to - heated to let some of - phase that doesn’t
- make a cone and - solvent evaporate. - move e.g. the paper Fractional Distillation
- placed into a filter - Used to separate mixtures with
- funnel. - Heating should be - Mobile Phase: - different boiling points
- stopped when small - solvent moves - Example: Crude Oil Separation
- Gravity pulls down - crystals form. - through the paper
- the liquid and solid - carrying different Crude oil is extracted from underground, it is a
- particles which are - The rest is left to - substances fossil fuel so non-renewable.
- caught by the filter - evaporate at room It is heated up and gas travels into a fractionating
- paper. - temp to get a good - Example: Drug Tests column which has a temp gradient from hot to
- sample of crystals. cold.
- Example: mixture of Rf Value = distance
pigment / distance Different compounds from the mixture of crude oil
- sand or salt, NaCl - Example: salt from turn into their condensed state at their boiling
solvent travelled
- and water - seawater points.
, Chapter 1 – Atomic Structure
- Molecule: chemically History of the Atom
- bonded atoms 1) John Dalton – Atom is a plain sphere that makes up everything
- Compound: 2) JJ Thomson – Created the plum pudding model, the whole sphere being positive and
- chemically bonded 2 2) with randomly scattered – charge electrons
- or more different 3) Rutherford – Discovered the concentrated part of positive in the middle. This was
- element atoms 3) from the gold foil experiment
4) Niels Bohr – Discovered shells and that electrons weren’t randomly scattered.
- Mixture: 2 or more 5) James Chadwick – Discovered neutrons and the model we have today
- atoms
Gold Foil Experiment
- Ions: atoms with a
- The experiment was carried out by Geiger & Marsden.
- charge
- Atoms don’t have an Experiment:
- overall charge as the - They shot alpha ray particles at a piece of gold foil.
- + and – subatomic - They expected for the alpha rays to shoot straight
- particles are equal - through the foil at a 180 degrees angle.
- Isotopes: atoms with Observations:
- the same number of - Some rays went straight through, showing that most of the atom was empty space.
- protons but different -- - Many rays deflected back at large and small angles thus showing that the atom had a
- number of neutrons. - dense positive nucleus in the middle.
, Chapter 2 – The Periodic Table
Group 1 (Alkali Metals)
Reactivity:
Observations when reacting with water
- Vigorous reactions with water
- Forms metal oxides Floats, gentle fizzing, gradually dissolves to
Li
- Forms ionic compounds (with G7) give a colourless solution.
- Reactivity increases going down Floats, vigorous fizzing, melts & Na rapidly
o Outer electron needs to be lost Na
dissolves to give a colourless solution.
o Going down, shells increase
o Electron shielding decreases Floats, very vigorous fizzing, burst of lilac
o Electrons can be lost easily K flame and K very rapidly dissolves to give a
colourless solution.
Properties: Sinks, explosive release of gas, and Rb
- Soft texture Rb instantaneously dissolves to give a
- Relatively low m/b points colourless solution.
- Low Densities
Sinks, violently explosive release of gas,
- M/b points decrease going down
Cs and Cs instantaneously dissolves to give a
o Metallic bonds become weaker
colourless solution.
o Because atoms get larger
o Outer electrons are further away from nucleus
o Attraction between + ions and delocalised electrons is weaker.
, Chapter 2 – The Periodic Table
Group 7 (Halogens)
Reactivity:
- Forms ionic compounds (with Group 1) The more reactive element displaces the less
- Reactivity decreases going down reactive element in a compound for example:
o Outer shell needs to gain an electron
o Going down, shells increase Cl2 + 2NaBr 2NaCl + Br2
o The force of attraction with nucleus Chlorine displaces Bromine as it is more reactive.
gets weaker
o Therefore, it’s harder to gain electrons
Chlorine Bromine Iodine
Properties: Cl2 (aq) Yellow/
Brown
- Exist as a diatomic molecule Orange
Solution
- Don’t conduct electricity Solution
- M/b points increase going down Br2 (aq) No
Brown
o Molecules become larger going down reaction/
Solution
o There are more electrons in each atom change
o Stronger intermolecular forces I2 (aq) No No
between the molecules reaction/ reaction/
o So, more energy is needed to change change
overcome these forces
, Chapter 2 – The Periodic Table
Transition Metals
- Located between groups 2 and 3 on the periodic table
- Large central block in the periodic table
- Creates compounds (salts)
Physical Properties:
- Good Conductors of Heat & Electricity
- Hard and Strong
- High Density and high melting points (except Mercury)
Chemical Properties:
- Multiple Oxidation states
- Therefore, coloured compounds
- e.g. Iron III Chloride
Comparison with Group 1
- Transition Metals are less reactive than Group 1 e.g. they don’t react readily with oxygen, water, and chlorine.
- Transition Metals have high density and high melting points, whereas Group 1 have low density and low mp.
- Transition Metals have to be heated strongly for a reaction to occur:
- 2Cu + O2 2CuO
, Chapter 2 – The Periodic Table
Development
1) John Dalton – He sorted elements in terms of atomic mass.
2) Johann Dobreiner – He sorted elements into threes (triads) as he noticed similar chemical properties.
3) John Newlands – He noticed that every eighth element had similar properties and ordered elements in terms of
3) masses. He called this the Laws Of Octaves. However, he was criticised as elements with different properties
3) were grouped as only atomic mass was looked upon.
4) Mendeleev – He ordered elements considering masses and properties. He is
4) significantly known for leaving gaps in his table as with his calculations, certain
4) elements were missing. He later, predicted properties of undiscovered
4) elements. As well as this, he put Iodine after Tellurium despite Iodine having
4) a higher atomic mass, to ensure that elements with similar properties were
4) grouped together.
5) Later Scientists – They arranged elements by their atomic numbers (protons) and added the noble gases
5) (Group 0). They also proved Mendeleev’s theory by adding in elements where Mendeleev had left gaps.
, Chapter 3 – Bonding, Structure & Matter
Ionic Bonding Covalent Bonding
- Between metals and non-metals - Between two non-metals
- Electrons are transferred - Electrons are shared
- Metals loses electrons ( + charge) - Both atoms share electrons, and charges aren’t gained
- Non-metals gain electrons ( - charge) - or lost
- Both are held together by opposite charges
Examples:
Examples:
Magnesium Oxide (MgO) Sodium Chloride (NaCl) Chlorine Molecule (Cl2) Water (H2O)
Limits of Dot & Cross Comparison of Ionic & Covalent
Diagrams: - Ionic forms lattices whereas covalent can’t as they aren’t ions.
- Cannot see states of matter - Covalent has low melting points whereas Ionic has high mp.
- Cannot see the transfer of electrons - Generally Ionic is solids, and covalent is liquid or gas.
- Cannot see relative sizes - Ionic has strong whereas covalent has weak intermolecular forces.
, Chapter 3 – Giant Covalent Structures
Diamond
Properties
- Hardest natural substance
- No intermolecular forces
- High melting/boiling points
- Doesn’t conduct electricity
- Insoluble in water
- Tetrahedral arrangement
- Transparent and sparkly
- Each carbon atom is bonded
- to 4 others, so no delocalised
- electrons to conduct electricity.
Uses
- Jewellery and Industrial drills
- This is because each carbon
- makes 4 strong covalent bonds
- So, the hardness, makes it
- suitable for its uses.
