Metals are a group of chemical elements that have played a fundamental role in everyday life and industry since time immemorial. They are known for being excellent conductors of electricity and heat, having high metallic luster, and maintaining a solid structure at room temperature, with exceptions such as mercury. In the field of chemistry, metals are those elements that, when chemically connected, form metallic bonds that allow the free movement of electrons, which gives them their unique physical and chemical characteristics.
In this article, we will learn in depth what metals are in the field of chemistry, what their notable properties are, their classifications, examples of metals, and their uses. We will also explore the differences between metals and non-metals, a crucial aspect to better understand our periodic table and the nature of these elements.
What are metals
Metals are elements that make up the majority of the periodic table and are found in various states of nature. Some can be found in pure form, although most are present in the form of minerals in the subsoil, and require different separation processes for their use. In the periodic table, they occupy the groups that make up the alkaline, alkaline earth and transition metals, among others.
One of the main characteristics of metals is that they possess metallic bonds, the result of the tight union of metal atoms and the free circulation of valence electrons. This “cloud” of electrons gives metals their great capacity to conduct electricity and heat, as well as their remarkable malleability and ductility. When metals combine with non-metals, such as chlorine, they generate ionic bonds that can form salts and other compounds, thus highlighting their chemical versatility.
Properties
The physical and chemical properties of metals make them essential materials for a multitude of applications. Below we detail some of the most important properties of metals:
- Thermal and electrical conductivity: Metals allow the free flow of electrons, making them excellent conductors of both electricity and heat. This is why metals are essential in the electrical industry and in systems that require thermal conduction.
- Malleability: Under the action of forces, many metals can be deformed without breaking, allowing them to be formed into different shapes, such as thin sheets or plates.
- Ductility: Metals can also be stretched without breaking, forming high-strength cables. This property is crucial in the construction industry and in the manufacture of electrical cables.
- Tenacity: Metals have the ability to withstand shock and other types of physical forces without breaking, making them ideal for creating solid structures and machinery.
- Metallic shine: The ability to reflect light gives metals their characteristic shine, making them highly appreciated in the creation of ornamental objects such as jewelry.
Classification of metals
Metals are grouped on the periodic table into various categories, based on their atomic structure and shared properties. These groups are:
- Alkali metals: They are elements belonging to group I, like lithium, sodium and potassium. They are all very reactive, which means that they are rarely found in a pure state in nature. They are soft, have low densities and melting points, and are excellent electrical conductors under normal conditions.
- Alkaline earth metals: They occupy group II and, although they are less reactive than the alkaline metals, they also have characteristics such as high conductivity and hardness. Examples of these metals include magnesium and calcium.
- Transition metals: Most metals belong to this group and are located in the middle of the periodic table. These include iron, copper and gold. These metals are known for their high strength and remarkably high melting points, as well as excellent thermal and electrical conductivity.
- Lanthanides: Also known as “rare earths,” these metals have an electronic arrangement that makes them particularly useful in advanced technological applications, such as in the manufacture of magnets and communication technologies.
- Actinides: Actinides, such as uranium and plutonium, are radioactive metals that play a key role in nuclear technologies. Their properties make them extremely valuable, but also dangerous if not handled properly.
- Transactinides: These are the so-called superheavy elements, such as seaborgium and lawrencium. They are synthesized in laboratories and are extremely unstable materials due to their radioactivity.
Examples and non-metals
Below are some examples of metals classified according to their groups in the periodic table:
- Alkali metals: Lithium (Li), sodium (Na), potassium (K).
- Alkaline earth metals: Magnesium (Mg), calcium (Ca).
- Transition metals: Iron (Fe), copper (Cu), gold (Au).
- Lanthanides: Lanthanum (La), cerium (Ce).
- Actinides: Uranium (U), neptunium (Np).
- Superheavy metals: Rutherfordio (Rf), seaborgium (Sg).
On the other hand, non-metals are elements that do not share the properties of metals, and their behavior is completely different. Within this category we find elements crucial to life, such as oxygen, nitrogen, and carbon. These elements do not conduct heat or electricity well, and they do not shine like metals, since they do not reflect light in the same way.
Nonmetals can be found in solid, liquid or gaseous state at room temperature. In addition, the bonds they form are not metallic but covalent, which means that when they react with each other, they share electrons instead of donating them or accepting electrons from other elements.
Importance of metals and the environment
Given the enormous importance of metals in industrial development, it is essential to take into account the environmental impact resulting from their extraction and use. Mining, in particular, generates waste and emits polluting gases that affect both ecosystems and human health.
Fortunately, many metals can be recycled, which reduces the need to continue to extract new materials. For example, aluminum is one of the most recyclable materials, as maintaining its reuse cycle saves energy and reduces environmental impact. Other recyclable metals include copper, iron, and steel.
It is therefore crucial to adopt appropriate recycling policies in order to minimise waste and preserve our metal reserves for the future.
The study of metals and their characteristics remains essential to understanding how we can use them responsibly and efficiently, both economically and environmentally. Materials science has allowed us to make enormous progress in the discovery of new alloys and advanced ways of obtaining metals in an increasingly sustainable way, something that will continue to be a decisive area in our long-term technological development.