On the question of the law of triangles in the periodic table

This is because the non-metallic nature of the same main group elements in the periodic table is weakened from top to bottom. The non-metallic properties of the same periodic elements are enhanced from left to right, for example, beryllium is weaker than the magnesium metal below it, and aluminum is also weaker than the magnesium metal on its left, and the strength of beryllium and aluminum cannot be judged according to the periodic table, then if it is left oblique, for example, potassium and magnesium, according to the periodic law, potassium metallicity is stronger than sodium above and stronger than calcium on the right, and magnesium is weaker than sodium on the left and calcium below, so magnesium metallicity is definitely weaker than potassium, and so on, how can left oblique be established?

Are beryllium and aluminum similar in nature?

Beryllium is a steel-gray metal; The melting point is 1283 °C, the boiling point is 2970 °C, the density gram cm , and the beryllium ionic radius Angstrom, which is much smaller than other metals. Thermal conductivity: w (m·k)200 The propagation rate of sound in it:

M S) 12870 Beryllium is chemically active and can form a dense surface oxide protective layer, which is stable in air even when red hot. Beryllium can react with dilute acid, but also soluble in strong alkali, showing both sexes. The oxides and halides of beryllium have obvious covalentity, the compounds of beryllium are easy to decompose in water, and beryllium can also form polymers and covalent compounds with obvious thermal stability.

Aluminum is a silvery-white shiny metal with a density of gram cm3 and a melting point of 2467. Valency 3. It has good thermal conductivity, electrical conductivity, and ductility, and ionization energy electron volts, although it is called a lively metal, but in the air, its surface will form a dense oxide film, so that it can not continue to interact with oxygen and water.

At high temperatures, it reacts with oxygen and releases a large amount of heat, and with this high heat of reaction, aluminum can replace metals from other oxides (thermite).

In the same main group, the top-down non-metallicity decreases and the metallicity increases. During the same cycle, the non-metallicity increases and the metallicity decreases from left to right. Therefore, the metallicity of beryllium is weaker than that of magnesium.

Aluminum is also less metallic than magnesium. In this way, the metallicity of beryllium is close to that of aluminum. The properties of other periods and the main group with similar laws are also similar.

As the atomic number increases, the charge number of the nucleus also increases, and the ability to attract electrons outside the nucleus increases. So roughly the yard radius of the main element will gradually decrease.

However, for elements with complex electronic configuration structure, the effect of this radius decline may be reduced due to the electron shielding effect.

The most obvious is the lanthanide series, because the electron shielding effect is very significant, resulting in a small difference in the yard radius of each element of the lanthanide series, which also causes the famous lanthanide contraction.

With the increase of the atomic number of the same period, the number of positive charges in the nucleus increases, the number of electron layers remains unchanged, and the attraction to the electrons outside the nucleus increases, so the atomic radius gradually decreases.

Common rules: in the same period, the metallicity of an element decreases from left to right, and the non-metallicity increases from left to right, and in the same family, the metallicity of an element increases from top to bottom, and the non-metallicity decreases from top to bottom; In the same period, the highest positive oxidation number of the element increases from left to right (except for those without positive valence), and the lowest negative oxidation number gradually increases from left to right.

The elements of the same family are similar in nature. During the same period of the main group of elements, the atomic radius decreases with the increase of the atomic number. In the same family, the atomic radius increases with the increase of atomic number.

If the electron configuration of the particles is the same, the radius of the anion is larger than that of the cation, and the radius decreases with the increase of the number of charges.

Periodic Table The periodic law should refer to the change in the number of nuclear charges of an element, and the number of electrons outside the nucleus. The number of stable electrons is 2 or 8, arranged according to the periodic table in the first column of the number of electrons outside the nucleus is 1, the second column is two, and so on. With each row down the periodic table, there is an additional layer of electron layers.

These are cyclical. It is also the increasing and decreasing metallic and non-metallic properties.

What is the difference in the nature of the fingers in the diagonal rule.

According to the smaller the number of nuclear charges, the weaker the ability to attract the outermost electrons, the stronger the metallicity, and the more the number of electron layers, the weaker the ability to attract the outermost electrons, the stronger the metallicity, so the lower the non-metallic main group of the periodic table, the more metallic it appears. In this way, it forms a diagonal property with the main group of the periodic table, which is relatively metallic.

The closer you are to the middle, the easier it is to show both sexes.

The change of the periodic table is a general law, not everything obeys this law, there are special ones in it, so this law is used as a good memory for general reasoning. The special must be remembered.

a The smaller the radius of the atom of the same periodic element, the stronger the ability of the nucleus to attract electrons outside the nucleus, and the less likely the atom is to lose electrons, so a is wrong;

b The metallicity of group A elements in the same period is stronger than that of group A elements, and if it is not in the same period, it is not necessarily, such as metallicity ca na, so b is wrong;

c Elemental sulfur is generated by dropping chlorine into hydrosulfuric acid solution, which indicates that chlorine oxidizes sulfur strongly, and the non-metallic properties of sulfur can be verified to be weaker than that of chlorine, so c is correct;

D o and f elements have no positive valency, except for o and f elements, the highest positive valency of other main group elements is equal to the outermost electron number of the atom of the element, so d is wrong, so c is chosen

The number of protons increases, the radius decreases, and the non-metallicity increases.