What are the chemical properties of selenium and what are the characteristics of selenium?

Summary. The "two main properties" of selenium

Characteristic 1: less content, large effect.

Selenium is an essential trace element (a mineral that is less than the body's body weight) and is found in very small amounts (6-20 mg).

However, it plays a vital role in the life activities of the human body and is closely related to the survival and health of people.

Feature 2: It cannot be synthesized independently, and needs to be supplemented by the outside world.

Selenium cannot be synthesized in the human body, it must be supplemented by external food (drinking water, eating plants and animals), and its intake is insufficient, unbalanced or lacking, which will cause abnormalities or diseases in human physiology to varying degrees.

What are the properties of selenium?

The "two characteristics" of selenium are one of the characteristics of small content, and the effect of selenium is a trace element (a mineral lower than the body weight of the human body) that is essential for the human body, and the content in the human body is very small (6-20mg). However, it plays a vital role in the life activities of the human body and is closely related to the survival and health of the human body.

Characteristic 2: It cannot be synthesized independently, and it needs to be supplemented by external selenium in the human body, and it must rely on the supplement of external food molds (drinking water, eating plants and animals), and its intake is insufficient, unbalanced or lacking, which will cause abnormalities or diseases in human physiology to different degrees of dispersion.

Selenium is a metalloidoid element that is more abundant, and it was listed as an essential trace element in the seventies, and its demand is relatively close to the amount of rent poisoning, the compounds of organic selenium are less toxic than those of inorganic selenium, and the selenium content in natural foods is very small, and most of the current selenium products are various products containing organic selenium. Selenium deficiency is an important cause of Keshan disease**. Selenium deficiency can induce liver necrosis, and selenium deficiency can induce cardiovascular disease.

People with mild or moderate selenium deficiency with subtle signs and symptoms are not obvious. Excessive intake of selenium will cause selenium poisoning, and its symptoms are: gastrointestinal disorders, ascites, anemia, hair profiling band loss, nail and ** deformation, liver damage.

Hope mine can help you.

1 All properties: group 16 (a) elements. Atomic number 34.

Stable isotopes 74, 76, 77. Oxidation states -2, +2, +4, +6. Density.

Melting point 217. Boiling point. Solid with a metallic sheen.

It can conduct electricity and heat. The metallicity is between sulfur and tellurium. Extremely poisonous!

There are 6 allotropic forms: (1) amorphous selenium, red and black glassy selenium, and colloidal selenium; (2) Crystalline selenium, divided into red. There are three types of selenium, monoclinic selenium and gray hexagonal crystal selenium.

The chemical properties are similar to sulfur. It burns in the air with a blue flame. It can be directly combined with hydrogen, halogens and various metals to form selenide.

Soluble in concentrated sulfuric acid, nitric acid and strong alkali. It can be extracted from waste from electrolytic copper plants or sulfuric acid plants. It can be used to make photocells, glass, enamel, pigments, paints, etc.

High-purity selenium is used in high-efficiency rectifiers. Selenium is an essential trace element in living organisms, which exists in living organisms in the form of low molecular weight compounds (including free selenium) and high molecular weight compounds, and is an essential trace element. The biological antioxidant effects of selenium can be divided into two categories: enzymatic and non-enzymatic.

The former is mainly carried out by selenium-containing glutathione peroxidase (GSH-PX). The antioxidant effects of selenium include: (1) scavenging lipid peroxidation radical intermediates; (2) decomposition of lipid peroxides; (3) repair the molecular damage of sulfur compounds caused by hydration free radicals (ho·, h·, etc.); (4) Hydration free radicals are removed or turned into stable compounds before they destroy living substances; (5) Catalyze the reaction of sulfhydryl compounds as protective agents.

Selenium has a synergistic effect with vitamin E in antioxidants. In addition, selenium also has anti-cancer and anti-cancer effects.

Arsenic does not contain selenium and contains arsenic (AS2O3).

Foods that contain more selenium:

Although butter, fish meal, lobster, mushrooms, pork kidney, garlic and other foods contain a certain amount of selenium, the absorption rate is not ideal. Nutritionists advocate supplementation of organic selenium, such as selenate polysaccharides, selenium yeast, selenium eggs, selenium-rich mushrooms, selenium-rich malt, selenium-rich gastrodia, selenium-rich tea, selenium-rich rice, etc.

Selenium intake is more related to the selenium content of the soil than to dietary patterns. Soils in the United States and Canada appear to contain enough selenium. A study of vegetarians and vegans in the United States found that they consumed enough selenium.

Selenium is found in many foods, but it's especially found in brazil nuts, whole grains (whole wheat bread, oatmeal, barley), white rice, and legumes.

Eggs contain more selenium than meat, and per 100 grams of food, pork contains micrograms of selenium, eggs contain micrograms of selenium, duck eggs contain micrograms of selenium, goose eggs contain micrograms of selenium, ginseng contains 15 micrograms of selenium, and peanuts contain micrograms of selenium. For example, the selenium content of grain produced in China's high selenium areas is as high as 4 8 milligrams per kilogram, while the grain in low selenium areas is milligrams per kilogram, a difference of 1000 times.

Selenium belongs to group A elements, and there are six kinds of oxidation states that can exist stably in general, such as +6, +4, +2, +1, 0, -2, and the representative compounds of various oxidation states are as follows

Selenic acid (H2SEO4, the oxidation state of selenium is: +6) and selenium dioxide (SEO2, +4).

Selenium dichloride (SeCl2, +2).

Selenium dichloride (Se2Cl2, +1).

Elemental selenium (se, 0).

Hydrogen selenide (H2Se, -2).

Selenium and metals with an oxidation state of +1 can produce two types of selenides, n-selenide (M2Se) and acid selenide (MHSE). An aqueous solution of positive alkali and alkaline earth metal selenides dissolves elemental selenium to form polyselenium compounds (M2Sen), similar to the formation of polysulfides from sulfur.

More than 40 kinds of diseases of human health and life are related to the lack of selenium in the human body, but selenium can not be synthesized by itself, the main ** of selenium is obtained from food, and the types of food with more selenium include seafood, meat, animal liver and kidney, egg products, nuts and other food types.

Cereal foods include wheat germ meal, cornmeal, empty pot cake, millet with skin, indica rice flour, etc.

Eggs are a good choice for selenium supplementation in terms of selenium content. Eggs are very rich in selenium, such as eggs, duck eggs, goose eggs and other foods, and the selenium content in such foods is incomparable to other foods. The order from highest to lowest is:

Goose eggs, duck eggs, eggs.

Pork pork is the most common, studies have found that every 100 grams of pork contains micrograms of selenium, pork selenium content is also considerable, so people who are deficient in selenium can supplement selenium by eating more pork in their daily life. Pay attention to the method of selenium supplementation in pork.

Garlic Garlic is a condiment and a vegetable, garlic is rich in selenium, which has the effect of improving immunity and can effectively remove active free radicals in the body. People who take selenium supplements can solve it by eating more garlic. Garlic can not only improve the body's immunity, but also the volatile substances contained in garlic also have a good anti-cancer effect.

Most seafood contains a lot of selenium, such as prawns, small shrimp, dried shrimp, small yellow croaker, oysters, abalone, etc. Among them, red shrimp, lobster, sardines, and tuna have the highest selenium content, so it is beneficial to eat these foods in moderation, but in moderation.

Purple potatoes are rich in selenium and fiber, which have the functions of promoting gastrointestinal peristalsis, cleaning up mucus, gas and putrefaction in the intestinal lumen, thereby improving the digestive tract environment and preventing the occurrence of hepatobiliary and gastrointestinal diseases.

Mushrooms are rich in selenium, which is easily absorbed by the body, and can be said to be a good selenium element in the body, and belongs to natural mushroom food, which is beneficial to the improvement of immunity and the prevention of diseases.

I hope you can adopt it, thank you.

Don't worry about the lack of selenium in the body, these foods are rich in selenium, and those who want to make up for it should quickly write it down.

Disease analysis: selenium-rich foods are first recommended sesame, malt and Chinese herbal medicine astragalus, followed by yeast, eggs, beer, seafood to red shrimp, lobster, tiger claw, tuna, etc., and then animal liver, kidney and other meat, and fruits and most vegetables do not contain much selenium, but the content of garlic and mushrooms is quite large, and asparagus contains selenium.

Selenium is a non-metallic element with the chemical symbol SE, which is located in the fourth period VI A group (element No. 34) in the periodic table of chemical elements. It can be used as a photosensitive material, a catalyst for the electrolytic manganese industry, an essential nutrient element for the animal body and a beneficial nutrient element for plants. Selenium exists in nature in two ways:

Inorganic selenium and plant-active selenium. Inorganic selenium generally refers to sodium selenite and sodium selenite, which are obtained from by-products of metal deposits; The latter is made by combining selenium with amino acids through biotransformation, and generally exists in the form of selenomethionine.

Selenium deficiency is an important cause of Keshan disease, and selenium deficiency is also considered to be an important cause of KBD. KBD is an endemic, multiple, degenerative osteoarthropathy. It occurs mainly in adolescents and seriously affects bone development and the ability to work and live later in life.

Excess selenium can cause poisoning. It is manifested as dry and brittle hair, easy to fall out, brittle nails, white spots and longitudinal lines, easy to fall out, ** injury and nervous system abnormalities, and death in severe cases.

Foods with more selenium and their selenium content are as follows (100 grams in micrograms).

Legume. Stir-fried white pumpkin seeds (, safflower beans (, tiger skin kidney beans (, flower peas, soybeans (, red kidney beans (, broad beans (, mung beans (, peanut kernels (, north tofu (, south tofu (.

Meat. Pork kidneys (kidneys) (, beef kidneys) (, duck livers, chicken livers, turkey livers, beef (lean) (, chicken breasts), pork (lean) (, lamb (lean) (.

Eggs. Quail eggs (, white-skinned eggs (, red-skinned eggs (.

Aquatic products. Chinese horseshoe crab (, shrimp skin (, red lady fish (, mackerel (mackerel (,mackerel (mackerel) (,mackerel (,mackerel) (,sea shrimp (,dace (,large yellow croaker) (,herring (,hairtail (,sea bass (,river shrimp (,moray eel (etc.).

Fruits and vegetables. Konjac powder (, alfalfa (, red cabbage moss (, cabbage moss (cabbage moss, cabbage sum) (, fresh dragon tooth beans (jade beans) (, garlic (purple skin) (, fresh dragon beans (, scoop white (vegetables) (, carrots (yellow) (, fungus (sunflower) (, edamame (green beans) (etc.)

Staple foods. Staple foods containing high selenium are very good ways to supplement selenium, such as rice, millet, pasta, ingested from staple foods, it is easier to promote the body's absorption and conversion, because staple foods are necessary for people to ingest every day, so long-term eating has greatly improved the health pattern of the human body.

Selenium is an important nutrient trace element essential for the human body, with a wide range of biological functions, such as anti-tumor, antioxidant, anti-inflammatory, anti-hypertensive, hypoglycemic and immunomodulatory, etc., is the only nutrient known to have a direct relationship with viral infection among various nutrients with immunomodulatory functions, which can enhance the ability of the human immune system to regulate, promote the phagocytosis function of macrophages, and is a component of glutathione peroxidase (GSH-PX) Therefore, selenium is known as the "expert" in regulating the body's immunity"。

The trace element selenium plays an extremely important role in human life activities, and is praised as the "spark of life" by the medical and nutritional circles at home and abroad, and enjoys the reputation of "longevity element" and "king of anti-cancer".