Is selenium a metal? How to judge whether an element is metal or not?

In this essay, we will talk about the question “Is selenium a metal” and also will discuss how to judge an element as a non-metallic element or a metallic element.

Properties of selenium

Is selenium a metal? Before talking about this question, we need to know the properties of selenium. Selenium is the 34th element in the periodic table, located in the middle of the oxygen group. Selenium is in the same period as oxygen, sulfur, and tellurium, which has 6 Valence electrons. 

There are two allotropes of selenium at room temperature: red selenium and gray selenium, very big differences in appearance and properties. Red selenium is a red crystal with semiconductor properties, which can be used in electronic components such as photovoltaic panels and light sensors. Gray selenium is a gray-black, metallic crystal with conductive and catalytic properties, which can be used in the manufacture of glass, cosmetics and other products.

Is selenium a metal?

The method of judging whether an element is metal or not is as follows:

1. From the sight of atomic structure, the number of electrons in the outermost layer of the atom of a metal element is generally less than 4.

2. From the point of view of chemical properties, the atoms of metal elements are easy to lose electrons in chemical reactions, showing reducibility, and the metal elements usually are used as reducing agents.

3. As a general rule, the metal has a metallic shininess, and most are silver-white.

Is selenium a metal? Different people have different views on the classification of selenium. However, selenium is closer to non-metallic elements in chemical properties, rather than metallic elements. Such as selenium has 6 valence electrons, and selenium reacts with oxides to form selenic acid and selenates and can form compounds with metals, nonmetals and halogens. Besides, the electrical conductivity of selenium is less than that of Sherwood elements such as sulfur, selenium, tellurium and multilateral graphene, whose electrical conductivity of elements is called "aurous properties". Therefore, selenium is classified as a non-metallic element.

The application of selenium

Selenium is one of the rare non-metallic elements. The amount of selenium in the earth's crust is much less than other elements. It is very difficult to find a mine that contains selenium elements. At present, the only independent mine where selenium exists in the world is found in the Enshi area of Hubei Province.

Selenium is widely used and can be applied in metallurgy, electronics, glass, ceramics, solar power and many other fields. For example, selenium has good photoelectric properties and can be used to manufacture photoelectric devices, such as selenium photocells, toner cartridges, and selenium photosensitive devices.

Selenium photocells can convert light energy into electricity and are widely applied in solar panels and photoelectric sensors. The downstream demand for selenium continues to grow with the development of the world economy and the occurrence of new application areas. So the price of selenium continues to go up.

The importance of selenium in the human body 

Selenium not only plays a key role in the industrial field but also is extremely important for human beings.

1. Selenium can improve the immune system's ability to recognize viruses, foreign bodies and lesions entering the body, improve the ability of immune cells to phagocytosis and sterilization, and fundamentally improve the human body's resistance to disease.

2. Selenium can inhibit the carcinogenic effect of diverse carcinogens, which is also a killer agent of cancer cells. And selenium can restrain the division and proliferation of cancer cells in the body. After cancer surgery, selenium supplementation can control the deterioration of the disease, reduce the toxic side effects of chemotherapy and radiotherapy, and speed up recovery.

Since selenium plays an important role in the human body. So how should we supplement the selenium content of the body? Eating main grains containing high selenium is a very good way to supplement selenium, such as rice, millet, and pasta, from the main grain intake. It is easier to promote human absorption and conversion of selenium because the main grain must be ingested every day. So long-term eating the main grains is very beneficial to human health.

Conclusion: 

At the end of the article, let's summarize today's topic of “Is selenium a metal”. Selenium is classified as a non-metallic element mainly because its chemical properties are more similar to non-metals. No matter whether selenium is a metallic element or not, it will not affect the important role of selenium in many fields. Especially it also plays an irreplaceable role in human health.