If you know the ordinal number of the element, how to determine which region it is in the period and

Knowing the atomic number is equivalent to knowing the number of electrons outside the nucleus, first of all, we must be familiar with the sublayers that each layer should have, according to the Pauli principle, the principle of the lowest energy can be obtained The electronic configuration formula can be obtained Finally, the number of cycles in the main group of elements (i.e., not yet arranged (n-1)d or (n-1)d is full, not arranged (n+1)s) There are several electrons in the outermost shell, that is, in the main group The principle of the subgroup is basically the same, but there are many exceptions, such as copper, you need to remember the electronic configuration. I think it's very simple for these Lanzhous to understand the structure of atoms. If you don't understand, don't force it.

The ordinal number of the element indicates the number of protons contained in the element, that is, the number of electrons (the number of protons is equal to the number of electrons), and then the number of periods of the element is determined by arranging the electrons (the number of periods is equal to the number of electron layers), and the family (determined by the number of electrons in the outermost shell). Of course, you still have to understand the periodic table to strengthen your memory and understanding. There are no "zones" in the periodic table.

It will be taught in the first year of high school).

Will the elements of the electrons not? The first layer is the second layer, the second layer is up to 8, the third layer is up to 8, the outermost layer is up to 8 times, and the outer layer is up to 18.

When I was learning, I memorized the periodic table, both horizontally and vertically.

The basics are clear at a glance when you buy a periodic table.

1. See if it is short-period (know the short period, that is, the first three periods, the number of electrons is less than 18) If so, write his atomic structural formula, such as mg, its atomic outer shell is the electronic formula.

It is a 2,8,2 structure, the first shell has a maximum of two electrons, the second shell is up to 8, and the third shell is up to 8 (the first three periods of the needle grip track is the most), it is the main group, there are several electron shells.

It is the first few beam cycles, such as mg is the second main group of the third cycle.

2, for not a short cycle, you need to work hard (in fact, there is a rule, but I forgot), this to learn the elements of each clan to memorize (very tired) sub-family elements do not need to judge, do not return to such a question.

3. If you want to learn this, it is recommended that you buy a copy of "Changjia Happy New Chemistry", which can help you understand chemistry thoroughly, and the rules you want to master are available in the state shed. Magazine ads have (don't doubt me, I'm not advertising).

Number of cycles = electron shell.

Number. (The collapse is a few electron layers, just in the first few cycles.) It should be noted that it is the number of electron shells of the atom) main group ordinal number = outermost shell electron number = highest valency.

However, f and o do not have the highest positive valency).

Such as the electron configuration of the S atom.

Wide old 2 8 6, so the group is slow in the third period, the first VIA group (VI is six, A is the main group).

Number of periods = number of electron shells. (It's just a few electron shells, just in the first period.) It is important to note the number of electron layers of the atom).

Main group ordinal number = outermost electron number = highest valency (but f, o do not have the highest positive valency).

For example, the electronic configuration of the S atom: 2 8 6, so the S element is in the third period, the VIA group (VI is six, A is the main group).

1. Hydrogen qīng

2. Helium hài

3. Lithium lǐ

4. Beryllium pí

5. Boron péng

6. Carbon tàn

7. Nitrogen dàn

8. oxygen yǎng

9. Fluorine dust fú

10. Neon nǎi

11. Sodium nà

12. Magnesium měi

13. Aluminum lǔ

14. Silicon gūi

15. Phosphorus líng

16. Sulfur liú

17. Chlorine lù

18, argon yà

19, potassium jiǎ

20. Calcium gài

21, scandium kàng

22. Titanium tài

23. Vanadium fán

24. Chromium gè

25. Manganese měng

26, iron tiě

27, cobalt gū

The first thing to do is to familiarize yourself with the periodic table.

Looking at it vertically, Qiaowu is the main element, and the law must be clear to everyone.

Horizontally, it is the same periodic element, the same periodic element, and the non-metallic properties are enhanced from left to right.

For example: beryllium, carbon, nitrogen, oxygen, fluorine (except for noble gases).

Sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine or more.

Questions you asked.

How to judge the metallicity and non-metallicity of different main group elements according to the periodic table?

It can be judged according to the transversal law.

There is also the problem of diagonal elements that are adjacent to the main family or adjacent periods, which is more complicated.

It can be judged by electronegativity:

For example, lithium is more metallic than magnesium, and sodium is more metallic than calcium.

Non-metallic: fluorine is stronger than simple oxygen, oxygen is stronger than chlorine, chlorine is stronger than nitrogen, nitrogen is stronger than bromine, bromine is stronger than iodine, iodine is stronger than sulfur, sulfur is stronger than phosphorus, phosphorus is stronger than arsenic, arsenic is stronger than silicon.

There are many electronegativity tables on the Internet, and you can understand it when you check it.

18 Elemental Secondary School Requirements Mastery:

Fluorine electronegativity 4, the strongest non-metallic; Oxygen, chlorine, chlorine in the old chemistry books was 3 and, now it has changed, is.

Nitrogen, originally 3) bromine, originally was, iodine (originally was, sulfur, originally was, carbon, phosphorus, arsenic, silicon, silicon already has a certain metallic properties).

Methods for the analysis of the atomic number of the main group elements.

The first thing to remember is the atomic number of noble gases:

Secondly, we need to know the family ordinal number corresponding to the column number:

Columns 1-2, respectively.

1. The second main family;

Columns 13-17 are the third to seventh main families.

The atomic number of the rare gas that is close to the previous period is pushed from front to back, which is the first main group or the second main group, respectively, and the atomic number of the rare gas that is close to the current period is pushed from back to front, which is the seventh to third main group.

For example, element 83 is close to the rare gas of the sixth period, element 86, radon, 85-seven, 84-six, 83-five, that is, element 83 is located in the fifth main group of the sixth period of the periodic table.

Periodic Table of Chemical Elements: A list of chemical elements sorted from smallest to largest according to their atomic number.