to Selenium:
Selenium is an essential metalloid that has been widely used in several industrial applications, including glass manufacturing, electronics, and metallurgy. It was first discovered by the Swedish chemist Jns Jacob Berzelius in 1817.
Selenium has unique physical and chemical properties, including its ability to exist in multiple isotopes, which makes it an interesting element to study. Properties and Characteristics:
Selenium is a non-metal, or metalloid, that can exist in several isotopes, including selenium-78, selenium-80, and selenium-82.
It has a melting point of 217 degrees Celsius, a boiling point of 685 degrees Celsius, and a density of 4.80 g/cm. Selenium is a highly reactive element that can form covalent bonds with other elements.
It is also a good conductor of electricity and has semiconducting properties. Selenium is a crucial component in several enzymes in the human body, including glutathione peroxidase, which protects cells from oxidative damage.
It also plays a vital role in thyroid hormone metabolism. However, excessive selenium intake can lead to selenosis, a condition that can cause hair and nail brittleness, gastrointestinal upset, and neurological problems.
Discovery and Identification:
Selenium was discovered by Berzelius while he was studying the byproducts of the sulfuric acid production industry in Sweden. He noticed a red precipitate that he initially thought was tellurium, another metalloid.
However, upon further study, Berzelius realized that he had discovered a new element. He named it selenium, derived from the Greek word “selene,” meaning moon, because of its similarity to tellurium, which he had named after the Earth.
Selenium’s atomic number is 34 on the periodic table, and its CAS number is 7782-49-2. It is a member of Group 16 and Period 4 and is located in the p-block.
Selenium has several stable and unstable isotopes, with the most abundant being selenium-80, which has a natural abundance of 49 percent. Selenium on the Periodic Table:
Selenium is located in Group 16, which is known as the oxygen group, and is also referred to as the chalcogens.
The oxygen group consists of elements that have six valence electrons, making them highly reactive. Selenium is located in Period 4, which means that it has four energy levels.
It is also located in the p-block, which is the block of elements that includes the non-metals, metalloids, and some of the metals. Selenium has an atomic mass of 78.96 g/mol and is a solid at room temperature.
It has several physical and chemical properties, including its metallic luster, semiconducting properties, and low reactivity. Selenium can exist in several oxidation states, including -2, +4, and +6, making it a versatile element in chemical reactions.
Physical and Chemical Properties:
Selenium’s physical and chemical properties are essential for its applications in different industries. For example, its semiconducting properties make it a crucial element in the production of photovoltaic solar cells.
Selenium is also used in the production of pigments for ceramics, glass, and plastics. Selenium’s atomic mass and density make it a useful element in metallurgy, where it is used as an alloying agent for other metals like copper and lead.
It also forms compounds with other elements like sulfur and oxygen, which have several industrial applications, including the production of fungicides, anti-dandruff shampoos, and nutritional supplements. Conclusion:
Selenium is an essential element with diverse applications in several industries.
Its unique physical and chemical properties make it an exciting element to study, and its role in human nutrition highlights its importance for life. However, excessive intake of selenium can lead to selenosis, and its toxicity must be understood to avoid adverse health effects.
Overall, selenium’s significance in different applications demonstrates the importance of understanding the properties and characteristics of the elements that make up our world. Common Uses of Selenium Element:
Selenium is a versatile element that has numerous applications across a wide range of industries.
Its properties, including its semiconducting behaviour, make it an essential component in various electronic devices, while its unique ability to interact with other elements gives it several applications in metallurgy, healthcare, and cosmetics. Industrial Applications:
One of the most common industrial applications of selenium is in the production of photoconductors.
Photoconductors are electronic devices that can convert light into electricity. They are widely used in photocopiers, x-ray machines, and other imaging technologies.
Selenium’s semiconducting properties make it ideal for this application. Another application of selenium in the industrial sector is in the production of solar cells.
Selenium is used as a component of the CIGS (copper indium gallium selenide) thin-film solar cells. These solar cells have high efficiency levels, making them a crucial element in the shift towards renewable energy sources.
Selenium is also used in the production of stainless steel. It is an essential component that gives the steel corrosion resistance and makes it less susceptible to environmental factors like moisture and heat.
Medical and Cosmetic Applications:
Selenium has several applications in the medical and cosmetic industries. One of the most common uses of selenium in these sectors is in the production of anti-dandruff shampoos.
Selenium sulfide is a compound that is used to treat dandruff and seborrheic dermatitis of the scalp. It works by reducing the production of skin cells, preventing the buildup of flakes.
Selenium is also used in pigments for ceramics, glass, and plastics. Its ability to form bright red pigments makes it an essential component in the production of art materials, cosmetics, and food coloring agents.
Selenium is also effective in treating scalp fungus, which can cause severe hair loss and other scalp conditions. The presence of selenium in shampoos can soothe the scalp while attacking the fungus, preventing the condition from spreading.
Toxic Effects of Selenium:
While selenium is an essential element, excessive intake can lead to severe health risks. Its toxicity has been well documented.
Here are some of the health and environmental implications of selenium toxicity:
Health Risks:
Excessive selenium ingestion can have acute and chronic effects on human health. Chronic exposure to high levels of selenium can lead to neurological defects, such as numbness, tingling, and loss of coordination.
In severe cases, it can even lead to paralysis and death. Selenium toxicity has also been linked with carcinogenic effects, such as the development of lung cancer.
While selenium is essential for many life processes, ingesting too much can cause poisoning. According to the National Institutes of Health (NIH), consumption of more than 400 micrograms of selenium per day can lead to symptoms such as nausea, vomiting, hair and nail damage, fatigue, and muscle tenderness.
The threshold for ingesting selenium varies depending on age, sex, and other health conditions.
Environmental Impact:
Selenium can also have adverse environmental effects.
For example, selenium can be toxic to aquatic life. When selenium is present in bodies of water, it can be absorbed by animals like fish and shellfish.
High levels of selenium in their tissues can cause deformities and reproductive problems that can affect the aquatic ecosystem.
Mercury toxicity in animals like fish is a direct result of selenium contamination of water bodies.
In areas with high mercury levels from mining activities, selenium is used to mitigate mercury pollution. Because selenium can selenate the mercury, it neutralizes its toxic properties.
However, this process produces methylmercury, which is even more dangerous to aquatic life and can cause severe health problems in people who eat contaminated fish.
Inhalation of selenium compounds can cause lung problems, including irritation, coughing, and bronchitis.
Prolonged exposure can lead to chronic obstructive pulmonary disease (COPD) and lung cancer. Conclusion:
Selenium is a highly versatile element with multiple applications across various industries.
It’s an essential component in electronic devices, solar cells, and stainless steel. It also has medical and cosmetic applications such as anti-dandruff shampoos and pigment production.
The toxic effect of selenium, on the other hand, is severe and can lead to neurological defects, lung problems, and carcinogenic effects. When taking selenium supplements or consuming products that contain selenium, it is essential to be mindful of the recommended dosage to avoid toxicity.
Care must also be taken in using this element in industrial production because of its potential for environmental contamination. Interesting Facts about Selenium:
Selenium is an intriguing element that has several unique properties and functions.
From its role in the human body to its affinity towards mercury, there are many interesting facts about this element that are worth exploring. Here are some interesting facts about selenium:
Properties and Functions:
Selenium is an essential element that is required in small amounts for several biological processes in the human body.
It is present in several enzymes, including glutathione peroxidase, which protects cells from oxidative damage. In addition, selenium plays a vital role in thyroid hormone metabolism.
Without enough selenium intake, the body cannot produce active thyroid hormones, leading to hypothyroidism. Interestingly, selenium also has an affinity for mercury.
When mercury is present in the body, selenium can bond with it and form a compound called seleno-mercury. This compound is less toxic than mercury alone, and it can be excreted from the body more quickly.
This is one reason why selenium supplements are often used as a way to reduce the toxicity of mercury in the body. Selenium’s affinity for mercury also makes it a critical element in environmental remediation efforts.
For example, in areas where mining and industrial activities have contaminated soil and water with heavy metals like mercury, selenium can be used to neutralize the toxic effects. Selenium binds with the mercury and breaks it down into a less harmful form that can be easily removed.
Cost and Availability:
Selenium is widely available in the Earth’s crust and is the 68th most abundant element. However, pure selenium is rare and not often found in nature.
Instead, it is typically obtained as a byproduct of copper, lead, and zinc mining. Selenium is often used as an alloying agent for these metals, and the byproducts of the process often contain selenium.
Because pure selenium is rare, it can be quite expensive. The current price for pure selenium ranges from $30 to $70 per gram, depending on the purity level.
This makes it one of the most expensive elements, even more than gold, which can cost around $50 per gram. However, selenium is not always expensive.
It is also used in some nutritional supplements in combination with other elements, and these supplements can be affordable. Additionally, selenium can be found in several foods, including Brazil nuts, certain types of fish, and grains.
Incorporating selenium-rich foods into your diet is an excellent way to ensure that you are getting enough of this essential element. Conclusion:
Selenium is a fascinating element with several unique properties and functions, from its crucial role in the human body to its affinity for mercury.
Its scarcity and high cost make it one of the most expensive elements, but it is widely available as a byproduct of other mining processes. The multiple industrial, environmental, and medical uses of selenium make it a crucial element in our modern world.
In conclusion, selenium is an essential element with diverse applications in various industries, from its use in electronics and solar cells to its presence in anti-dandruff shampoos and pigments. Its properties and functions, including its role in the human body and its affinity towards mercury, make it a fascinating element to study.
However, it is important to be aware of the potential toxic effects of selenium and to use it responsibly. Despite its high cost and limited availability in its pure form, selenium can be obtained through certain foods and supplements.
Overall, understanding the significance of selenium and its varied applications highlights the importance of this element in our daily lives. FAQs:
1.
What is selenium used for in industrial applications? Selenium is used in the production of photoconductors, solar cells, and as an alloying agent in stainless steel.
2. What are the medical and cosmetic applications of selenium?
Selenium is used in anti-dandruff shampoos to treat scalp conditions and in the production of pigments for ceramics, glass, and plastics. 3.
What are the health risks associated with selenium toxicity? Excessive selenium ingestion can lead to neurological defects, carcinogenic effects, and symptoms such as nausea, hair and nail damage, and muscle tenderness.
4. How does selenium interact with mercury?
Selenium has an affinity for mercury and can bond with it to form a compound called seleno-mercury, which reduces the toxicity of mercury and facilitates its excretion from the body. 5.
Is selenium expensive and easily available? Pure selenium is rare and can be expensive, costing around $30 to $70 per gram.
However, selenium can be obtained as a byproduct of copper, lead, and zinc mining, and is also present in certain foods like Brazil nuts and fish. 6.
How can selenium be used in environmental remediation efforts? Selenium can be used to neutralize the toxic effects of mercury in contaminated soil and water by binding with mercury and converting it into a less harmful form that can be easily removed.