Physical and chemical properties of silver and their impact on its price

Silver (Ag) is a valuable precious metal characterized by low chemical reactivity and exceptional antibacterial properties. At the same time, it is susceptible to tarnishing under the influence of sulfur compounds present in the air. Its key features include inertness to oxygen and water at room temperature, as well as the highest electrical and thermal conductivity of all metals.

In this article, we discuss in detail the chemical properties of silver, the mechanism of its tarnishing, and its wide application in medicine and the chemical industry, resulting from its unique atomic structure.

Table of contents

• What are the key chemical properties of silver?
• Why does silver turn black when exposed to air?
• How do silver ions exert their antibacterial effect?
• What is the practical application of silver in medicine?
• What is the significance of silver in the chemical industry?

What are the key chemical properties of silver?

Silver (Ag) is a transition metal belonging to group 11 of the periodic table. As a precious metal, it is distinguished by its low chemical reactivity, thanks to which it remains inert to oxygen and water under normal conditions. It is resistant to non-oxidizing acids, but reacts with strong oxidizing agents such as nitric acid (V) or hot, concentrated sulfuric acid (VI).

In chemical compounds, silver most often occurs in the first oxidation state, less frequently in the second or third. Its physical properties deserve special attention—silver has the highest electrical and thermal conductivity of all metals, which makes it a material of exceptional technological importance.

Why does silver turn black when exposed to air?

Although silver does not react directly with pure oxygen, it undergoes corrosion processes over time. The main cause of tarnishing is the presence of hydrogen sulfide in polluted air. This gas reacts with the metal surface, leading to the formation of black silver sulfide (Ag₂S), which is responsible for the characteristic tarnishing.

This process can be further accelerated by:

• sulfur oxides,
• ozone, even at room temperature.

As a result, the shiny surface of silver gradually loses its luster, becoming covered with a thin layer of reaction products with volatile sulfur compounds.

How do silver ions exert their antibacterial effect?

Silver has strong antibacterial, antifungal, and antiviral properties, which are due to silver ions (Ag⁺). These ions are responsible for the biological activity of this element.

Silver ions bind to the cell membranes of microorganisms, causing permanent damage. They then penetrate the cells, where they block the action of key enzymes responsible for metabolic processes. As a result, cellular respiration is inhibited and microorganisms are deprived of their energy source.

In addition, silver ions prevent DNA and RNA replication, effectively stopping the multiplication of pathogens. This multifaceted action makes silver an extremely effective disinfectant.

What is the practical application of silver in medicine?

Thanks to its antimicrobial properties, silver plays an important role in preventing infections and is an important element of modern medicine. Its use covers many areas of clinical practice.

Specialized dressings containing silver are used in the treatment of burns and ulcers, supporting the healing process and tissue regeneration. Silver nanoparticles are used to coat surgical instruments, which significantly reduces the risk of infection during invasive procedures. This element is also used in the production of medical clothing – impregnating fabrics with silver effectively limits the growth and spread of pathogens in hospital environments.

Examples of silver applications in medicine include:

• protection of burn wounds,
• supporting the treatment of ulcers,
• accelerating tissue regeneration,
• covering surgical instruments,
• reduction of the risk of infection during procedures,
• impregnation of medical clothing,
• limiting the spread of pathogens.

What is the significance of silver in the chemical industry?

Silver plays an important role in the chemical industry, both as an effective catalyst for many reactions and as a component of important chemical compounds.

Silver halides, such as silver chloride and bromide, are particularly important. Their light sensitivity makes them play a key role in traditional photography, enabling the image to be fixed as a result of the photochemical decomposition of silver halides. This process involves the reduction of Ag⁺ ions to metallic silver under the influence of light.

Nowadays, silver is also widely used in modern technologies. Due to its highest electrical conductivity among metals, it is used, among others, in electronics, hi-tech technologies, the automotive industry, and in the renewable energy sector—for example, in the production of photovoltaic cells.

Diamine silver(I) hydroxide, known as Tollens' reagent, is also widely used in analytical chemistry. Thanks to its mild oxidizing properties, it is used to detect:

• aldehydes,
• reducing sugars.

A characteristic example of its use is the silver mirror reaction, in which silver ions are reduced to their metallic form. This reaction is used in:

• silvering of mirrors,
• production of decorative Christmas tree baubles.