Typical transition elements
The elements below have properties that are typical of transition elements:
- chromium, Cr
- manganese, Mn
- iron, Fe
- cobalt, Co
- nickel, Ni
- copper, Cu
The table shows the melting point and density of some transition elements, compared to three metals in the periodic tableA 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. that are not transition elements.
Metal | Position | Melting point | Density |
Sodium | Group 1 | 98掳颁 | 0.97 g/cm3 |
Magnesium | Group 2 | 650掳颁 | 1.74 g/cm3 |
Aluminium | Group 3 | 660掳颁 | 2.70 g/cm3 |
Chromium | Transition elements | 1890掳颁 | 7.19 g/cm3 |
Manganese | Transition elements | 1240掳颁 | 7.20 g/cm3 |
Iron | Transition elements | 1538掳颁 | 7.87 g/cm3 |
Cobalt | Transition elements | 1492掳颁 | 8.90 g/cm3 |
Nickel | Transition elements | 1453掳颁 | 8.90 g/cm3 |
Copper | Transition elements | 1083掳颁 | 8.92 g/cm3 |
Metal | Sodium |
---|---|
Position | Group 1 |
Melting point | 98掳颁 |
Density | 0.97 g/cm3 |
Metal | Magnesium |
---|---|
Position | Group 2 |
Melting point | 650掳颁 |
Density | 1.74 g/cm3 |
Metal | Aluminium |
---|---|
Position | Group 3 |
Melting point | 660掳颁 |
Density | 2.70 g/cm3 |
Metal | Chromium |
---|---|
Position | Transition elements |
Melting point | 1890掳颁 |
Density | 7.19 g/cm3 |
Metal | Manganese |
---|---|
Position | Transition elements |
Melting point | 1240掳颁 |
Density | 7.20 g/cm3 |
Metal | Iron |
---|---|
Position | Transition elements |
Melting point | 1538掳颁 |
Density | 7.87 g/cm3 |
Metal | Cobalt |
---|---|
Position | Transition elements |
Melting point | 1492掳颁 |
Density | 8.90 g/cm3 |
Metal | Nickel |
---|---|
Position | Transition elements |
Melting point | 1453掳颁 |
Density | 8.90 g/cm3 |
Metal | Copper |
---|---|
Position | Transition elements |
Melting point | 1083掳颁 |
Density | 8.92 g/cm3 |
Worked example
Compare the properties of sodium and chromium. How does the data show that chromium is a typical transition element, and sodium is a typical group 1 metal?
Chromium has a much higher melting pointThe temperature at which a solid changes into a liquid as it is heated. than sodium. The densityA 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). of chromium is also greater than sodium. Most transition elements have high melting points and densities, so chromium is a typical transition element. The group 1 elements have low melting points and densities, so sodium is a typical group 1 element.
Question
Predict the differences in the hardness and strength of nickel and potassium. Give a reason for your prediction.
Nickel is harder and stronger than potassium. The reason for this prediction is that nickel is a transition element and potassium is in group 1.