Chemistry - Metals

Transition Metals

High Melting point-coloured compounds-high density-used as catalysts

corrosion definition

the oxidation of a metal that weakens the metal

rusting definition

iron reacts with oxygen and water to make hydrated iron oxide (rust)

barrier method

painting, covering in oil or plastic

sacrificial protection

cover in more reactive metal which reacts instead of iron

galvanising

cover in zinc

alloy definition

a mixture of a metal and another metal or non metal element

why are alloys stronger than normal metals

because the layers cant slide

properties of copper

resists corrosion-conducts electricity-malleable

properties of gold

resists corrosion-expensive-shiny

properties of aluminium

resists corrosion-low density

use of copper

to make wires

use of gold

jewellery

use of aluminium

used to make aircraft

metal + acid

salt + hydrogen

metal + water

metal hydroxide +hydrogen

metal + oxygen

metal oxide

more reactive than carbon

use electrolysis to extract

less reactive than carbon

heat with carbon

ore definition

rock that contains enough metal to extract for profit

why heat with carbon

carbon is more reactive and displaces metal from ore

electrolysis disadvantages

uses electricity-uses a lot of energy - costly

bioleaching

bacteria grown on low grade ore and solution of metal ions made, metal extracted with displacement

phyto extraction

grow plants that absorb metal ions, burn plants and extract metal from ash

disadvantage of bio leaching

slow

disadvantage of phyto extraction

expensive

life cycle assesment

getting raw material-manufacturing and packing-using product- disposal

reduction

gain of electrons loss of oxygen

oxidation

loss of electrons gain of oxygen