There are several ways to classify metals, but a common method is based on their physical and chemical properties.
- Metallic elements can be divided into three categories:
- Alkali metals (Group 1): soft, highly reactive, and have low melting points. Examples include lithium, sodium, and potassium.
- Alkaline earth metals (Group 2): have higher melting points and densities than alkali metals. Examples include beryllium, magnesium, and calcium.
- Transition metals: have variable valence electrons and are generally harder and more dense than the alkali and alkaline earth metals. Examples include iron, copper, and gold.
- Based on their properties, metals can also be classified as:
- Ferrous and non-ferrous metals: Ferrous metals contain iron and non-ferrous metals do not.
- Precious and base metals: Precious metals are rare, expensive and have high economic value. Examples include gold, silver, and platinum. Base metals are more common and have lower economic value. Examples include copper, lead, and zinc.
- Some metals can be classified based on their reactivity:
- Noble metals: are not easily oxidized or corroded and have low reactivity. Examples include gold, silver, and platinum.
- Reactive metals: are easily oxidized or corroded and have high reactivity. Examples include aluminum and sodium.
- Lastly, Metals can also be classified based on their crystal structure:
- Crystalline metals: have a regular arrangement of atoms in their crystal structure, examples include aluminum and iron
- Amorphous metals: have a disordered arrangement of atoms in their crystal structure, examples include metallic glass.
