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Air
1. Dry air contains non metal elements such as: nitrogen oxygen and argon
2. Air also contains small amounts of non-metal compounds such as: CO2 and water vapour
Simple molecular substances
1. Have very low melting and boiling points
2. They are low because the intermolecular forces are weak
3. Very little energy is needed to overcome the forces
4. They have no free electrons moving around so they cant conduct electricity
Ionic crystals
1. The earths hydrosphere is all the water on earth
2. Hydrosphere is mostly water with some salts
3. When water evaporates dissolved salts from solid crystals
4. Salts are ionic compounds. Ions have either a positive or a negative charge and are arranged in a giant 3-D pattern called a lattice
5. The strong force of attraction between positively charged ions and negatively charged ions is called an ionic bond
6. Ionic compounds have high melting and boiling points
  1. Because a large amount of energy is needed to overcome the strong intermolecular forces in the lattice
7. Ionic compounds do not conduct electricity when solid but do when they are melted or dissolved in water because the charged ions can move
8. Na+ and Cl- make NaCl; Mg2+ and Cl- make MgCl2
9. SO4 2- is a molecular ion
Testing for ions
1. Solutions of some ionic compounds make a precipitate of an insoluble compound when they mix.
2. Calcium Ca2+
  1. White precipitate
3. Copper Cu2+
  1. Light blue precipitate
4. Iron(II) Fe2+
  1. Green precipitate
5. Iron(III) Fe3+
  1. Red Brown precipitate
6. Zinc Zn2+
  1. White precipitate
7. Negative carbonate ions are identified by adding dilute acid and looking for fizzing
  1. Because CO2 is released
8. Negative chloride, bromide, iodide and sulfate ions are identified by adding dilute silver nitrate or dilute barium chloride and looking for precipitates
Metals minerals and ores
1. The litosphere is the rigid outer layer of the earth made up of the crust and the upper mantle
2. Minerals are solid with atoms or ions arranged in a regular arrangement or lattice
3. Silicon oxygen and aluminium are very abundant in the litosphere
4. Rocks contain metal minerals called ores
5. Extracting metals by heating their oxides with carbon is a redox reaction as both oxidation and reduction happen
6. Burning metals can only be used for elements less reactive than carbon
Diamond and Graphite
1. They are giant carbon covalent structures
2. Diamond
  1. Bonds are very strong and need a large amount of energy to break them. This is why it has a high melting point and wont dissolve in water
  2. There are no free particles in diamond so it doesnt conduct electricity
  3. Each carbon atom has 4 bonds in a tetrahedral lattice
3. Graphite
  1. Each carbon atom is strongly bonded to three others in sheets
  2. The sheets are strong but there is a weak bond between the layers so they can slide over eachother
  3. There are free moving electrons between the layers so it conducts electricity
Formula mass
1. The relative formula mass of a compound is the sum of the relative atomic masses of all the atoms in its formula
2. The gram formula mass of an element or compound is its relative atomic mass in grams
3. percentage of metal in mineral = total mass of metal atoms/gram formula mass
Electrolysis
1. Passing a current through an ionic compound when it is molten or dissolved in water
2. The compound being broken down is called the electrolyte - electrolytes break down as the current passes through them
3. It is used to extract more reactive metals because their oxides cannot be reduced by carbon
4. Metals form at the negative cathode because metals are positive ions
5. Negative ions such as chloride and oxide move to the positive anode
Metals
1. Are malleable - can be hammered into shape
2. The atoms are held by metalic bonds - atoms are arranged in a regular pattern or giant lattice
3. Metallic bonds are very strong and need a lot of energy to melt or reshape them
4. The metal ions lose their outer shell electrons to form positive ions in solid metals- this forms a sea of electrons that move around
5. The attraction between the + ions and sea of electrons is so high - so metals have high melting and boiling points
6. Metals conduct electricity as they have electrons that can move
7. In pure metals, all the atoms are the same size and can roll over each other - so metals are malleable
8. Environment
  1. Lead mercury and cadmium are poisonous
  2. Extracting and purifying metal ores needs a lot of energy
  3. They have a very small yield
  4. Some minerals contain sulphur and during extraction sulfur dioxide could be made

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	Created by Fin Carson about 7 years ago