Specification Point 5.1 C:
Recall that most metals are transition metals and that their typical properties include:
a) high melting point
b) high density
c) the formation of coloured compounds
d) catalytic activity of the metals and their compounds as exemplified by iron
- Most of the known metals are transition metals, which have all of the typical properties of metals.
- They are very hard and strong and are good conductors of heat and electricity.
- They are highly dense metals and have very high melting points:
- Titanium melts at 1,688ºC whereas potassium melts at only 63.5ºC, not far off the average cup of tea!
- Transition metals can have more than one oxidation state as they can lose a different number of electrons, depending on the chemical environment they are in:
- Chromium forms up to three ions with different charges: Cr2+, Cr3+ and Cr6+.
The transition elements on the Periodic table
- Compounds containing transition elements in different oxidation states will have different properties and colours.
- Transition metals are often used as catalysts.
- These are substances which speed up the rate of a reaction without being used up in the process as they do not chemically participate in the process.
- Common transition metal catalysts include:
- Iron which is used in the Haber Process.
- Vanadium pentoxide (V2O5) is used in the Contact Process to produce sulfuric acid.
The colours produced by ions of the transition elements
Corrosion of Metals
Specification Point 5.2C:
Recall that the oxidation of metals results in corrosion.
- Corrosion is the destruction of materials by chemical substances in their environment which act on them over a period of time.
- Most metals can corrode in the presence of oxygen to form the corresponding metal oxide.
- Corrosion is caused by redox reactions:
- The metal loses electrons and is oxidised while the oxygen gains electrons and is reduced.
- Rusting is the name given specifically to the corrosion of iron in the presence of water and oxygen from the air.
Edexcel GCSE Chemistry Notes
Want to aim for a Level 9?
See if you’ve got what it takes. Test yourself with our topic questions.
Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.
More Edexcel GCSE (9-1) Chemistry Revision Resources