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B1 Chemistry - Coggle Diagram
B1 Chemistry
B1.33 The relationship between the atomic structure and physical and chemical properties of metals
Key terms:
Ions: atoms that have lost electrons (positive ions) or gained electrons (negative ions)
Delocalised electrons: 'free' electrons that are not associated with any single atom
Corrosion: the process where metals react with substances in the air to form oxides, carbonates, hydroxides or other compounds
Physical properties
Lattice
Particles packed closely together in a 3 dimensional grid arrangement
The structure consists of metal ions and a sea or cloud of delocalised electrons
This is because the atoms in the lattice have lost their outer shell electrons
Metallic bonding
The attraction between the positive ions and the negative electrons holds the particles together in the lattice
Conductivity (electrical and thermal)
The delocalised electrons are free to move throughout the lattice
This means they carry an electric current (flow of charge)
The delocalised electrons can move and vibrate
This means they can transfer thermal energy from one to another through the metal
malleability / ductility
Metals are malleable (they can be hammered into shape)
Metals are ductile (they can be drawn into wires)
This is because of their layered structure
If a force is applied to a metal, the layers can slide without disrupting the bonding
Strength
The close packing of the particles explains their high density
There are twice as many delocalised electrons in Mg2+ than Na+
This is because magnesium has 2 electrons in it's outer shell - so therefore forms 2+ ions
This means there are twice as many 2+ ions and delocalised electrons
Therefore there is a greater electrostatic attraction between the positive ions and delocalised electrons in magnesium
This means more energy is needed to overcome these forces in magnesium
Which means it has a higher melting point than sodium
Chemicals properties
Group 1
Group 1 metals are all highly reactive
Group 1 metals react with water to form hydrogen gas and the metal oxide
Group 1 metals all have a single electron in their outer shell and so they form ionic compounds containing 1+ ions
The outer electrons are further from the nucleus as you move down the group
Therefore there is a weaker force of attraction between the negative outer shell electrons and the positive nucleus
Transition meals
Much less reactive with oxygen and acids compared with group 1+2
Iron will rust (form ion oxide) only when in contact with air containing water vapour
Other transition metals react even more slowly, which makes them resistant to corrosion
The reaction of transition metals with acids is variable - it depends on the metal and the acid
iron will react with hydrochloric acid to produce iron chloride
In both cases hydrogen is also produced and the iron forms Fe2+ ions
iron will react with sulphuric acid to produce iron sulphate