Chemically stable means that the outermost electron number is 2 and 8 pairs

The stability we are talking about here is relative stability, not absolute stability.

1. Metallic elements.

The number of electrons in the outermost shell of an atom is generally less than 4 in a chemical reaction.

It is easier to lose the outermost electrons in the middle, and the subouter shell becomes the outermost shell, usually reaching a stable structure of 8 electrons, and the smaller the number of electrons in the outermost shell, the easier it is to lose electrons and chemical properties.

The livelier. 2. The number of outermost electrons of non-metallic element atoms is generally more than or equal to 4, and it is easier to obtain electrons in chemical reactions, and the outermost shell reaches a stable structure of 8 electrons, and the more outermost electrons, the easier it is to obtain electrons, and the more active the chemical properties. Therefore, the properties of an element, especially its chemical properties, are very closely related to the number of electrons in the outermost shell of its atom.

3. Noble gas elements.

The outermost shell of the atom has 8 electrons (helium is 2), and the chemical properties of the noble gas element are relatively stable, and generally do not react with other substances. Nature is determined by structure. Therefore, we usually refer to this structure with 8 electrons in the outermost shell (2 electrons in the outermost shell when it is the first shell) as a stable structure.

The number of electrons in the outermost shell of carbon is 4, which is neither easy to gain electrons nor easy to lose electrons, and is relatively stable!

The right HE is 2 and the noble gas is 8

Nothing, nothing

Satisfy. This is a coordination compound, c and o have 2 covalent bonds, and a lone pair of electrons of o enters the empty p orbital of c to form a coordination bond, so it is a co triple bond.

Structurally, carbon monoxide has a very weak polarity, where the positive charge is biased towards oxygen. However, in middle school, it is not required to consider the problem of polarity through structural qualitative consideration, so the positive electricity bias is biased towards carbon directly through electronegativity.

There is a coordination bond in the carbon monoxide molecule, and out of the three bonds formed, the carbon atom emits 2 electrons and the oxygen atom emits 4 electrons.

The figure below shows the electronic formula at the top and the structural formula at the bottom (where the arrow represents the coordination bond, which also means that both electrons are provided by oxygen atoms).

Hope it works for you.

This is a covalent compound... It is a bit complicated and requires the theory of atomic structure sp hybrid orbitals·· It's about general chemistry in the freshman year.,It's not junior high school and high school knowledge.,It's right that he's stable.,But it doesn't seem to be easy to explain with high school and junior high school theories.····

High school doesn't need to be that complicated, if you're in high school, understand it that way.

Replacing c and o with n n, the principle is that c and o have two pairs of covalent bonds, at this time oxygen has 8 electrons and carbon 6 electrons, oxygen coordinates one of its remaining two pairs of electrons to carbon, and puts it on the two pairs of electrons c and o, at which time c reaches saturation. The absolute valency value + the number of electrons in the outermost shell of the atom is very small, and it is only used in the early years of junior high school and high school to determine the valency of simple compounds.

Really not satisfied c = o, o satisfied, c not satisfied.

B and Al are both group A elements with certain similarities in chemical properties.

For example, B can form B(OH)4- ions, and Al can form Al(OH)4- ions.

Atoms with the same number of electrons in the outermost shell may have some similarity in chemical properties.

Generally, the outermost electron number of elements of the same main group element is the same, and the chemical properties are similar, but there is also gradation.

In fact, metallic and non-metallic properties are relative, but the relative strength is different, and some elements may show some properties of metals and some properties of non-metals.

Aluminum, boron is at the junction of metals and non-metals, so they all have partial metallic and non-metallic properties, as for the same chemical properties, it is generally so, some unique properties are naturally different, but commonalities do exist, for example, aluminum chloride is a covalent molecule, and chlorine and other metals generally form ionic compounds, so aluminum forms covalent compounds like boron, and there is an electron deficiency property, but this is generally discussed in universities.

There are two main manifestations: (1) The number of electrons in the outermost shell determines the chemical properties of the element. Although the properties of the elements are also affected by other factors, such as the number of nuclear charges, the number of electrons in the outermost shell is the main factor. Therefore, the outermost shell has the same number of electrons and similar chemical properties.

2) In the periodic table, the outermost electron number is the same as that of the main group element, and the chemical properties of the same main group element are generally considered to have a certain similarity, even hydrogen and sodium have a certain similarity (both can lose an electron, obvious positive valence, etc.).

Atoms with the same number of outermost electrons are elements agreeing to the main group on the periodic table, that is, on the same column. For example, the equation h li na k ru is in the same family, o and s night markets are in the same family, n p and other night markets are in the same family, and their chemical properties are similar.

H cannot be 8 electrons in any state.

He], such as li, be are not.

The situation of IIIA is slightly exceptional.

The ionic compound that forms the R cation, R is the stable structure of 8 electrons, such as the ionic compound of Al.

If a tri-coordinated covalent compound with (III) valence is formed, it is an unsaturated structure of 6 electrons.

Such as H Bo, BF, AlCl gas.

If there is a coordination bond to form a tetracoordination structure, then the stable structure of 8 electrons is also satisfied.

Such as B(OH), BF, AL CL, AL(OH) - and so on.

Group IV is basically a stable structure of 8 electrons, such as Co, CCL, H SiO4, etc.

Summary. In general, the number of shared electron logarithms and the absolute valency value are equal, so we can have the following judgment methods:

Step 1: See if there is hydrogen or noble gas elements in the substance. If there is, then the 8-electron structure will certainly not be satisfied.

Step 2: Think about whether these substances have written their electronic formulas during the learning process, and if they have written, they must have satisfied the 8-electron structure.

Step 3: Mark the valency of each element in the substance, calculate it according to "the outermost electron of the atom + absolute valence value", if the result is equal to 8, then the stable structure of 8 electrons is satisfied.

How to determine the outermost atom of a compound with a stable structure of 8 electrons.

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In general, the logarithm of shared electrons and the absolute valency value are equal, so we can have the following judgment methods: The first step of the stove cover: see if there is hydrogen element or rare hidden gas element in the substance.

If there is, then the 8-electron structure will certainly not be satisfied. Step 2: Think about whether these substances have written their electronic formulas during the learning process, and if they have written, they must have satisfied the 8-electron structure.

Step 3: Mark the valency of each element in the substance, calculate it according to "the outermost electron of the atom + absolute valence value", if the result is equal to 8, then the stable structure of 8 electrons is satisfied.

First of all, the range of elements on the original question is too wide, which is generally the basis for judging the liveliness of non-metallic elements, and also the basis for judging the strength of non-metallic elements.

Non-metallic = oxidizing, that is, the ability of an element to gain electrons. Comparing the strength of non-metallic properties is equivalent to the stability of non-metallic elements and hydrogen gases and gaseous hydrides under different conditions of difficulty. In gaseous hydrides, h is generally positive and other non-metallic elements are negative.

In short, it is different in difficulty and different in non-metallic properties. There's no reason for that, it's a law. The electron gain and loss are the same, h loses electrons, and non-metallic elements gain electrons, depending on the difficulty of the reaction conditions.

Chlorochlorobromo-iodine is a four-type halogen.

Difficulty: From easy to difficult.

Gaseous hydride stability: HF HCl HBR HI elemental oxidation: F Cl BR I

By the way, the second method of judging the non-metallic properties of non-metallic elements:

Reactive non-metals can replace inactive non-metals with br2+2ki 2kbr+i2 from compounds

Note: F cannot displace other substances in solution because F2 cannot displace other substances in solution because F2 meets water**.

The number of electrons in the outermost shell of an element.

is the most stable at 8", which is only for the periodic table.

It doesn't necessarily apply to all elements in the higher tremor front.

Compared with the top elements, the number of electron shells is less, and the maximum number of medium and liquid layers is three layers (except for potassium and calcium, but the electrons in the outer shell of potassium ions and calcium ions are also three layers). For these elements, the outermost shell holds up to eight electrons, so 8 electrons are the most stable.