metals Flashcards
metallic bonding
- metals have a giant metallic lattice structure
- there are strong electrostatic forces of attraction between the fixed metal cations and the sea of mobile electrons
- the metal cations are held in fixed positions in a lattice structure by the strong electrostatic forces of attraction
physical properties of metals mp bp
- high mp bp (except group I metals) as
SBEP
S: metals have giant lattice structures
B: with strong electrostatic forces of attraction between the fixed metal cations and the sea of mobile electrons
E: which requires a lot of energy to overcome
P: thus metals have high mp bp
physical properties of metals electricity conductivity
can conduct electricity as they have free mobile electrons to carry charges and transfer heat
physical properties of metals ‘material’
metals are malleable and ductile
in our the metals, the metal atoms are the same size and arranged in an orderly arrangement, thus the metal atoms cam slide past easily when a force is applied
physical properties of metals density
metals have high densities (except group I metals) as the metal;s are closely packed together and hence there are more atoms per unit volume, resulting in high density
definition of alloy
an alloy is a mixture of a metal with one or more other elements
examples of alloy
brass = copper + zinc
bronze = copper + tin
steel = iron + carbon
why are alloys harder and stronger than pure metals
since different elements are present in an alloy, the size of atoms are also different. the atoms of the added elements distrupts the orderly arrangement of the layers of atoms due to their different sizes, making it difficult for the layers of atoms to slide past one another.
the more reactive a metal is,
- the more easily/ readily the metal atom loses its electrons
- the more easily the atom is oxidised
- the stronger the reducing agent
- forms compounds which are more thermally stable with stronger bonds
reaction of metals with water steam and hydrochloric acid
5.3528
5: reacts with cold water to form aq metal hydroxide and hydrogen
3: reacts violently and explosively with steam
5: reacts woh=th steam to form metal oxide and hydrogen
2: reacts very violently and explosively with acids
8: reacts with acids to form salt and hydrogen gas
( only metals above hydrogen in the reactivity series is able to react with and displace out the hydrogen from the acid)
potassium group I
- reacts violently/ explosively with water
- fizzing is heard as bubbles of gas (hydrogen) is given off
- potassium metal may burn is lilac flame
- potassium floats and darts about water surface ( low density )
sodium group I
- reacts vigorously with water
- fizzing is heard as bubbles of gas (hydrogen) is given off
- sodium metal burn in a yellow flame
- sodium forms a molten ball which floats and darts about the water surface
calcium
- reacts quickly/ readily with water
- calcium sinks to bottom, producing bubbles of gas (hydrogen)
displacement reactions of metal
reduction of oxide of a less reactive metal
format eg. zinc being more reactive than copper, loses electrons more readily and displaces copper from aq copper(II) sulfate
format eg. aluminium, being more reactive than iron, loses electrons more readily and reduces iron(III) oxide to form iron
reduction of metal oxides with carbon/hydrogen
everything below C
silver gold
everything below C + 1 (Z)
everything below C:
reduced by heating with carbon (coke) or carbon monoxide to produce carbon dioxide and metal
silver gold:
reduced by heating alone
everything below C + 1:
reduced by heating with hydrogen to produce steam and metal
[ the more reactive the metal , the more stable the metal oxide formed, the less likely the oxide will be reduced by heating with carbon or hydrogen]
