What are the rules of the periodic table of elements

What are the rules of the periodic table of elements

The regularity of the elements and their compounds in the periodic table
1.1 atomic radius
(1) Except for the first period, the atomic radii of other periodic elements (except inert gas elements) decrease with the increase of atomic number;
(2) From top to bottom, the atomic radius increases with the number of electron layers
1.2 element valence
(1) Except for the first cycle, from left to right, the highest positive valence of elements increases from alkali metal + 1 to + 7, and the negative valence of non-metallic elements increases from carbon group - 4 to - 1 (except Fluorine has no positive valence and oxygen has no + 6 valence);
(2) The highest positive and negative valence of elements in the same main group are the same
1.3 melting point of single substance
(1) In the same period, with the increase of atomic number, the melting point of metallic elements increases, while that of nonmetallic elements decreases;
(2) From top to bottom, the melting points of metallic elements decrease, while those of nonmetallic elements increase
1.4 metallic and nonmetallic properties of elements
(1) In the same period, the metallicity decreases from left to right, and the nonmetallic increases;
(2) The metallicity of the same main group elements increases from top to bottom, while the nonmetallic decreases
1.5 acidity and basicity of the highest valence oxides and hydrates
The stronger the metallicity of the element, the stronger the alkalinity of the hydrate of the highest valence oxide; the stronger the non metallicity of the element, the stronger the acidity of the hydrate of the highest valence oxide
1.6 nonmetallic gaseous hydrides
The stronger the nonmetallic elements are, the more stable the gaseous hydrides are. The stronger the nonmetallic elements of the same period are, the stronger the acidity of the gaseous hydrides aqueous solution is. The stronger the nonmetallic elements of the same group are, the weaker the acidity of the gaseous hydrides aqueous solution is
1.7 oxidizability and reducibility of simple substance
The stronger the metallicity of general elements is, the stronger the reducibility of elemental matter is, and the weaker the oxidability of oxide ions is; the stronger the non metallicity of elements is, the stronger the oxidability of elemental matter is, and the weaker the reducibility of simple anions is
2. Infer the rule of element position
The rules should be kept in mind when judging the position of elements in the periodic table
(1) The period number of elements is equal to the number of electron layers outside the nucleus;
(2) The ordinal number of the main group element is equal to the outermost electron number;
(3) The final difference is the family number. When the difference is 8, 9 and 10, it is VIII. When the difference is greater than 10, it is 10. The final result is the family number
Respondent: beryu - Tongsheng level 1 2-23 19:08

What's the rule of elements from left to right in the periodic table? Thank you

In the same period of the periodic table, from left to right, the number of protons of the element atoms increases gradually. In the same period, from left to right, they are arranged in such a way as (metal) elements (transition) elements and (nonmetal) elements. In the same group, the (chemical properties) of the elements are very similar
❤ your question has been answered ~ (> ^ ω)^

How to remember the relationship between the properties of elements in the periodic table?
For example: Elements in the same period from left to right, the ability to get electrons is enhanced
Wait, is there any trick or formula?

Because
In the same period, the atomic radius decreases from left to right
In the same period, the oxidizability of elements increases from left to right
The atomic radius of the same main group increases from top to bottom
From top to bottom, the reducibility of the same main group element is enhanced (because it changes from nonmetal to metal)
The main family elements separate the main family

What is the relationship between atoms and elements
The concept mentioned in scientific Explorer is very strange. Who can tell me what it is?

① Element is a macroscopic concept, which means the same kind of atoms with the same proton number (nuclear charge number)
Atom is a microcosmic concept, which represents the smallest unit of an element
② Atoms or ions with the same number of protons and different numbers of neutrons belong to the same element. Atoms or ions with the same number of protons and different numbers of neutrons are called isotopes