Transition metals
Most Shiny element that is a good conductor of electricity and heat, and which forms basic oxides. are A metal that is located in between group 2 and group 3 (labelled as group 13 on some modern periodic tables) and has brightly coloured compounds.. They include iron and other metals used in construction, gold and other precious metals. The transition metals are placed in the central part of the A tabular representation of all known elements in order based on atomic number, eg all the noble gases are found on the right of the periodic table..
Typical properties
Compared to other metals, the transition metals have these typical The characteristics of something. In chemistry, chemical properties include the reactions a substance can take part in. Physical properties include colour and boiling point.:
- high The temperature at which a solid changes into a liquid as it is heated.
- high A measure of compactness and the ratio of mass to volume. It is usually measured in kilograms per metre cubed (kg/m3) or grams per centimetre cubed (g/cm3).
- they form coloured A substance formed by the chemical union of two or more elements.
- they (and their compounds) can act as A chemical or other agent that brings about a change in something else without necessarily changing itself. It can also mean a person or thing that causes an event.
Remember that these are typical properties - some transition metals may not show one or more of them. For example:
- mercury The process that occurs when a solid turns into a liquid when it is heated. at just -39掳C, so it is a liquid at room temperature
- scandium has a similar density to aluminium in A vertical column in the periodic table containing elements with similar chemical properties. 3, so pieces of scandium are relatively lightweight
Iron as a transition metal
Iron (Fe) has the typical properties of transition metals.
High melting point and density
The table shows the melting point and density of iron, compared to three non-transition metals. Iron, a transition metal, has a higher melting point and a higher density than the non-transition metals.
| Metal | Melts at | Density | Position |
| Iron | 1538掳颁 | 7.87 g/cm3 | Transition metals |
| Sodium | 98掳颁 | 0.97 g/cm3 | Group 1 |
| Magnesium | 650掳颁 | 1.74 g/cm3 | Group 2 |
| Aluminium | 660掳颁 | 2.70 g/cm3 | Group 3 |
| Metal | Iron |
|---|---|
| Melts at | 1538掳颁 |
| Density | 7.87 g/cm3 |
| Position | Transition metals |
| Metal | Sodium |
|---|---|
| Melts at | 98掳颁 |
| Density | 0.97 g/cm3 |
| Position | Group 1 |
| Metal | Magnesium |
|---|---|
| Melts at | 650掳颁 |
| Density | 1.74 g/cm3 |
| Position | Group 2 |
| Metal | Aluminium |
|---|---|
| Melts at | 660掳颁 |
| Density | 2.70 g/cm3 |
| Position | Group 3 |
Coloured compounds
Metals that are not transition metals usually form white or colourless compounds. Like other transition metals, iron forms coloured compounds. The table shows some examples of these.
| Compound | Colour |
| Iron(II) hydroxide, Fe(OH)2 | Pale green |
| Iron(III) hydroxide, Fe(OH)3 | Orange-brown |
| Iron(III) oxide, Fe2O3 | Red-brown |
| Compound | Iron(II) hydroxide, Fe(OH)2 |
|---|---|
| Colour | Pale green |
| Compound | Iron(III) hydroxide, Fe(OH)3 |
|---|---|
| Colour | Orange-brown |
| Compound | Iron(III) oxide, Fe2O3 |
|---|---|
| Colour | Red-brown |
Catalytic activity
Catalysts are substances that speed up the A measurement of how quickly a reaction takes place. without being used up in the reaction. Iron is the catalyst used to make ammonia in the The industrial chemical process that makes ammonia by reacting nitrogen and hydrogen together.. Iron(III) oxide is a catalyst used to make hydrogen by reacting carbon monoxide and steam together.