Let s talk about alkali metal elements in detail and what alkali metal elements include

Alkali metals refer to all the metal elements in the A group of elements in the periodic table, at present, there are six kinds of lithium (Li), sodium (Na), potassium (K), rubidium (RB), cesium (CS), and francium (FR), the first five exist in nature, francium can only be produced by nuclear reactions, and does not exist in nature. Alkali metal is a very metallic element, its elemental substance is also a typical metal, showing strong electrical and thermal conductivity, potassium and sodium alloy is used as a thermal conductive agent for nuclear reactors, the elemental element of alkali metal is too high because of high reactivity, can not be preserved in the natural state, the existence of alkali metal salts in nature, potassium, sodium is a macro element in the ocean, and also plays an important role in living organisms; The rest are light and rare metal elements, which are very rare in the earth's crust.

Note: This article focuses on the general properties of each alkali metal element, please refer to the corresponding entry for history, industrial information, and more specific properties.

Note: Because the half-life of francium is only 21 minutes and it is extremely unstable, it has not yet been made into a pure element, so the properties of francium are not discussed for the time being.

Alkali metals: The six metallic elements in group A in addition to hydrogen in the periodic table.

Alkali metals contain six elements: lithium (Li), sodium (Na), potassium (K), rubidium (B), cesium (CS), and francium (FR).

Alkali metal is a collective name for six metal elements: lithium, sodium, potassium, rubidium, cesium, and francium. Francium (FR) is a radioactive element.

Therefore, high school is not considered, except for lithium hydroxide.

In addition to the medium and strong alkali, the hydroxide of the rest of the alkali metals is a strong alkali. Solubility of alkali metal salts.

The biggest feature is solubility. Removes a very small number of anions.

The alkali metal salts are insoluble in water, and almost all alkali metal salts are soluble in water and completely ionized in solution.

Atomic structure of alkali metal elements

Similarity: The atoms of alkali metal elements have only 1 electron in the outermost shell and 8 electrons in the secondary outer shell (of which the li atom has only 2 electrons in the subouter shell). Therefore, in chemical reactions, the atom of the alkali metal element always loses the outermost electron and shows +1 valence.

Degeneration: The nucleus of alkali metal elements such as LI, NA, K, RB, CS etc.

The number of outer electron shells gradually increases, and the atomic radius.

As it gradually increases, the attraction of the outermost electron to the kernel gradually weakens, the ability of filial piety near power loss gradually increases, and the metallicity of the element gradually increases.

The physical properties of alkali metals and their variations

Color: Silvery-white metal (CS with a slight golden sheen).

Hardness: small, and with LI, NA, K, RB, CS, the hardness of the metal gradually decreases. This is due to the gradual increase in the number of electron layers of atoms, the gradual increase in the radius of atoms, and the gradual weakening of the forces between atoms. Alkali metals have low hardness and can be cut with a knife.

Alkali metals have a low melting point: lithium with the highest melting point is, and the melting point of cesium is. With atomic number.

The melting point of the elemental gradually decreases.

Alkali metals are less dense: Li, Na, K are less dense than water, and lithium is less dense than kerosene.

density. As the atomic number increases, the density of alkali metals gradually increases. However, the density of potassium is less than that of sodium, and there is an "abnormality" phenomenon.

This is because the density of the metal depends on the action of two aspects, on the one hand, the atomic mass, on the other hand, the atomic volume, from sodium to potassium, the increase in atomic mass plays a smaller role than the increase in atomic volume, so the density of potassium is smaller than that of sodium.

The younger primary group elements (except hydrogen) in the periodic table are all alkali metal elements.

Alkali metal is the collective name of the six metal elements of group I in the periodic table: lithium, sodium, potassium, rubidium, cesium, and francium, and is also the general name of their corresponding elemental substances.

The alkali metal element alkali metal in the periodic table refers to all the metal elements in the A group of elements in the periodic table, currently there are six kinds of lithium (Li), sodium (Na), potassium (K), rubidium (RB), cesium (CS), and francium (FR), the first five exist in nature, and francium can only be produced by nuclear reactions. Alkali metal is a strong metallic element, and its elemental element is also a typical metal, showing strong electrical and thermal conductivity. Alkali metals have high elemental reactivity and exist only as salts in their natural state, while potassium and sodium are macroelements in the ocean and also play an important role in living organisms; The rest are light and rare metal elements, which are very rare in the earth's crust.

It is a metallic element that can form alkalis.

For example, NA, K, CA

Alkali metals: The six metallic elements in group A in addition to hydrogen in the periodic table.

1. Alkali metals refer to the six metal elements in the periodic table in group A except hydrogen (H), namely lithium (Li), sodium (Na), potassium (K), rubidium (RB), cesium (CS), and francium (FR).

2. According to IUPAC, alkali metals belong to the A group of elements in the periodic table. Alkali metals all have one outermost electron belonging to the s orbital, so this group belongs to the s region of the elemental slippery periodic table. The chemical properties of alkali metals show very clear homologous behavior and are the best example of elemental periodicity.

Although hydrogen (H) belongs to the group of good vola, it appears to have a chemical properties that are very different from alkali metals, so it is not considered an alkali metal.

Alkali metal elements: refer to the six metal elements in group A except hydrogen (H) in the periodic table, including lithium (Li), sodium (Na), potassium (K), rubidium (RB), cesium (CS), francium (FR), located on the far left of the periodic table. The number of electrons in the outermost shell of alkali metals is 1.

Alkali metals – family characteristics, as the same side family, alkali metals have many similar properties:

1. Most of them are silvery-white metals (except for cesium, which has a golden-yellow luster).

2. The texture is soft and can be cut with a knife.

3. The density is small, and the melting point and boiling point are relatively low.

4. The chemical properties are active, and it is easy to lose electrons to form cations with +1 charge.

Alkali metals – are they in **? Alkali metal elements are very common in life.

Lithium element - used in light alloys, atomic reactors, etc., lithium-ion batteries with lithium alloy as the anode material, widely used in electronic products and electric vehicles to power electricity.

Sodium - The main component of table salt is sodium chloride; Sodium carbonate, also known as soda ash or soda, is often used to soften water and as a rust remover; Sodium baking soda bicarbonate is often used as a silver age leavening agent, and it also has important applications in industrial production fields such as papermaking.

Potassium – Potassium chloride and potassium nitrate are important fertilizer fertilizers for crops; Potassium hydroxide is used in the manufacture of chemical products such as soap and alkaline batteries.

Rubidium element - rubidium and its compounds are used in electronic devices, catalysts, special glass and other fields.

Cesium element – The most important use of cesium is in the manufacture of atomic clocks.

No, such as ammonia, tetramethylammonium hydroxide, etc., which do not contain metal ions.

Not necessarily, in addition to metal ions, there can also be ammonium ions, NH4+, which can replace metal cations, such as ammonium chloride NH4Cl, ammonium sulfate (NH4)2SO4

Alkali is generally composed of metal ions and hydroxide ions, and the special case ammonia is also a base, and the chemical formula is NH3·H2O, which can also be expressed as NH4OH, and does not contain metal elements, so it is wrong for alkali to contain metal elements. The algebraic sum of positive and negative valencies in compounds is 0, and all metallic elements show positive valence, and only non-metallic elements can show negative valence.

Not necessarily, such as ammonia monohydrate (weak base).