What are the halogen elements of halogen elements, and what are halogen elements?

1. Fluorine (f): Fluorine gas is a light yellow gas at room temperature and is highly toxic. The single halogen is white and transparent and colorless in aqueous solution. Fluorine and hydrogen fluoride (hydrofluoric acid) are highly corrosive to glass.

2. Chlorine (Cl): Chlorine is yellow-green gas at room temperature. Aqueous solution (solubility 20 data):

Chlorinated water is yellow-green in color. The solution with carbon tetrachloride is yellow-green, yellow-green in benzene solution, AGCL is white, and it is insoluble in water. The copper chloride solution is blue (the complex formation is dark green), the ferric chloride solution is yellow, and the ferrous chloride solution is light green.

3. Bromine (br): liquid bromine, which is a dark reddish-brown liquid at room temperature. In aqueous solution:

Bromine water is orange, and the solubility may appear in the following colors due to different concentrations: yellow, brownish-red (reddish-brown). The CCL4 solution is orange-red, the benzene solution is orange-red, and the alcohol solution is orange-red.

Barium bromide solution: colorless, copper bromide solid: black crystalline or crystalline powder, magnesium bromide solution:

Colourless. 4. Iodine (I): Iodine is a purple-black solid at room temperature. Aqueous solution (solubility 20 data):

Iodized water: brownish-yellow, solubility due to different concentrations, the following colors may appear in the question: brownish-yellow, purple (red), brown).

In carbon tetrachloride solution purple, benzene solution purple, alcohol solution brown.

Halogen elements refer to periodic group A elements. Including fluorine (F), chlorine (Cl), bromine (br), iodine (I), astatine (AT), referred to as halogen. They are found in nature as typical salts and are halogenic elements.

With the increase of molecular weight, the dispersion force between halogen molecules gradually increases, the color becomes darker, and their melting point, boiling point, density, and atomic volume also increase in turn. Halogens are oxidizing, and fluorine elements are the most oxidizing.

Physical progression of halogen elements: from f2 to i2, the color changes from light to dark; The state ranges from gaseous, liquid to solid; The melting and boiling point gradually increases; The density gradually increases; Solubility gradually decreases.

Atomic Structure: Similarities The outermost shell has an equal number of electrons, both of which are 7

All are easy to obtain electrons, all are oxidizing, and all show -1 valence.

Progressive The number of electron layers gradually increases.

The ability to gain electrons is weakened.

Non-metallic and oxidizing properties are weakened.

1.Similarity.

1) Physical properties: halogen elements have less density, less hardness and lower melting point.

2) Halogens are all active non-metallic elements, which can react with H2, active metals, water, etc. Such as reaction with H2: X2+H2===2Hx, reaction with water:

x2+h2o===hx+hxo (x is cl, br, i), 2f2+2h2o===4hf+o2

2.Degrading.

1) Physical properties: In the order of F, CL, BR and I, the color of halogen elements deepens sequentially, the melting and boiling points increase sequentially, and the density increases sequentially.

2) With the increase of the atomic number of the element, the oxidation of halogen elements gradually decreased, and the reducibility of anions gradually increased. That is, oxidation: F2>Cl2>Br2>I2, reducibility: F-(3) With the increase of the atomic number of the element, the halogen element and H2 are more and more difficult, the stability of the corresponding hydride is gradually weakened, the reduction is gradually enhanced, the acidity of the aqueous solution is gradually enhanced, and the melting and boiling points of HCl, HBR and HI increase sequentially.

3.Particularity.

1) Fluorine has no positive valence and no oxygenated acid; The chemical properties of fluorine are particularly active, and it generates HF and O2 when exposed to water, which can react with noble gases, and hydrofluoric acid can corrode glass. Silver fluoride is easily soluble in water and has no photosensitivity properties.

2) Chlorine is easy to liquefy, hypochlorous acid has a bleaching effect, and can be sterilized and disinfected.

3) Bromine is the only liquid non-metallic element at room temperature, bromine is volatile, a small amount of bromine should be stored with water liquid seal, bromine has a strong corrosive effect on rubber.

4) Iodine is a purple-black solid, easy to sublimate, and iodine turns blue when it encounters starch.

Halogenated elements, namely the seventh group VIIA, include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (AT), referred to as halogens.

Physical properties: With the increase of molecular weight, the dispersion force between halogen molecules gradually increases, the color becomes darker, and their melting and boiling points.

The density and volume of the original characters also increase sequentially.

Chemical properties: strong oxidation: the chemical properties of halogens are due to the fact that the outermost shell is 7 electrons, and it is easy to obtain one electron, so halogens are strong oxidants, which only exist in a chemical state in nature.

Moreover, with the increase of the number of electron shells, the atomic radius gradually increases, the gravitational attraction of the nucleus to the outer electrons gradually weakens, the electron-obtaining ability gradually weakens, and its oxidation gradually weakens. Therefore, fluorine is the most oxidizing of these elements.

The halogen elements are fluorine, chlorine, bromine, iodine, astatine. Halogens are referred to as pulses.

In nature, it is found in typical salts, which are salt-forming elements.

With the increase of molecular weight, the dispersion force between halogen molecules gradually increases, the color becomes darker, and their melting point, boiling point, density, and atomic volume also increase in turn.

The chemical properties of halogens are very similar, they have 7 electrons on the outermost electron shell, and there is a tendency to obtain an electron to form a halide ion with a stable octagonal structure, so halogens are oxidized, and the smaller the atomic radius, the stronger the oxidation, so fluorine is the most oxidizing of the element.