Newlands: Conceived the law of octaves, arranged in increasing atomic weight, some elements were grouped incorrectly and the table was incomplete.

Mendeleev: Increasing atomic weight, switched the order of some elements, left gaps for undiscovered elements. He predicted the properties of these elements and was proven right.

Modern: Increasing proton number, noble gasses included. (Mendeleev had to correct order due to presence of isotopes).

Oxygen:
All react rapidly and from a metal oxide layer when exposed.

Chlorine:
React rapidly with chlorine.

Water:

• Lithium: Fizzes rapidly (gas), turns water alkali.
• Sodium: Fizzes more rapidly, melts, forms a ball and moves across the surface.
• Potassium: Fizzes more rapidly, releases hydrogen that burns with a lilac flame.
  [Hydroxides formed]

Halogens are diatomic, forming a covalent molecule.

The melting point of halogens increases as you go down the group.

Reactivity decreases as you move down the group.

In graphite, each carbon atom bonds with three other carbon atoms in a hexagonal repeating pattern, meaning that for every carbon atom, there is a free delocalised electron that is free to carry charge. Graphite can slide due to weak IMF between layers.

Carbon nanotubes are a cylindrical form of graphene, they can conduct electricity and heat well, have a high tensile strength and have a high surface area to volume ratio. These nanotubes can be used in the production of electronics but also in the reinforcement of tennis rackets.

Buckminsterfullerene is an altered form of graphene with a near-spherical shape. They have a very high surface area to volume ratio. They have the ability to deliver drugs in the body due to their hollow shape. They can also be used as catalysts and in lubricants due to their ability to roll.

Metallic bonds form between two metals.They are held together by the electrostatic attraction between positive metal ions and a sea of delocalised electrons.

Alloys contain two or more different metals, this disrupts the uniform structure of the metal and prevents layers from sliding, making alloys harder, more durable and more resistant to corrosion.

Nano particles typically have a diameter from 10nm to 100nm. They have a large surface area to volume ratio.

Nanoparticles can be used at catalysts, in electronics and medicines. Silver nanoparticles have antibacterial properties.

Relative atomic mass = ((Abundance of A x Mass of A) + (Abundance of B x Mass of B)) / 100

Mass = Relative Formula Mass x Number of Moles

The limiting reactant is the reactant that gets used up first in the reaction, it limits the reaction. Using reactants in excess ensure that all of the limiting reactant will have been used up.

A higher percentage yield in industry ensures that minimal waste is produced, production is optimally efficient and maximum profit is made. It could also reduce consumer cost.

Factors that result in a yield < 100:

• Reaction may be reversible (didn't go to completion).
• Some of the reactants may have been left in the aparatus.
• Undesired side-reactions may have taken place.
• Reactants may not be pure.

Reactions with higher atom economies render a reaction more efficient and aids in sustainable development. It means that less waste is produced in the reaction.

Concentration is the amount of solute that has dissolved in a certain amount of solvent.

Method (adding alkali to acid):

• Equipment cleaned with distilled water and the solution you are using to stabilize the pH and prevent contamination.
• Measure out 25cm^3 of acid (of a known concentration) using a volumetric pipette; this should be drawn up using a pipette filler, reading it from the bottom of the meniscus.
• Add the acid to a conical flask and then add a few drops of phenolphthalein indicator.
• Measure out a volume of alkali using a burette (recording the initial volume).
• Place the conical flask on a white tile with the burette tap above the flask.
• Slowly add the alkali to the acid in the flask, adding dropwise when the endpoint is nearly reached.
• When the solution just changes from colourless to slight pink. Record the volume of alkali used.
• These steps should be repeated until concordant results are obtained (within 0.1cm^3 of each other).

1 mol of any gas at room temperature and pressure occupies 24dm^3 of space.

More unreactive metals will exist in a pure form within the Earth. More reactive metals will be found in their metal ore forms. Metals that are less reactive than carbon can be extracted from their ores through the use of carbon reduction.

The higher a metal is on the reactivity series, the more reactive it is and the more elements it can replace from their compounds.

A more reactive metal will have a greater tendency to form positive ions.

K, Na and Li will react violently with acid. Tin and lead react slowly with warm acid and copper, gold, etc do not react with acid.

If the pH of a solution decreases by one order of magnitude, the concentration of hydrogen ions within increases by a factor of 10.

Acids can be neutralised with alkalis (soluble metal hydroxides) or bases (insoluble metal hydroxides).

Forming Crystals Method:

• Pour given dilute acid into a beaker and heat it slightly with a bunsen burner.
• Add metal oxide or carbonate in excess and stir until gas is no longer given off (all the acid has reacted).
• Filter off excess metal oxide or carbonate using filter paper and a funnel.
• Pour the solution into an evaporating basin.
• Use an electric heater to slowly evaporate off the water from the solution.

Within exothermic reactions, energy is transferred from the system to the surroundings.

Exo: Combustion, oxidation, neutralisation, respiration, combustion.

Cathode: 2H{2}(g) --> 4H+ + 4e[-]
Anode: O{2}(g) + 4H+ + 4e[-] --> 2H{2}O(g)