Region 1, s: including two columns of IA and IIA * * *; The valence electron shell is ns 1 or 2(n≥ 1).
Features: valence electron number = main family ordinal number = outermost electron number.
Note: ① Not all elements of valence electron shell ns 1 or 2 are in S region, except He (in P region).
(2) Except H, they are all metal elements.
2. Area P: including Ⅲ a to ⅶ A and zero family * * * six families and six columns; The valence electron shell is ns2 np 1-6(n≥2).
Features: ① Total number of valence electrons = main family ordinal number (except zero family);
② Non-metallic elements are dominant.
Note: He is in the P region, but it has no P electrons.
periodic table of elements
3. Zone D: including Ⅲ b to ⅶ b and ⅷ ⅷ ⅷ ⅷ ⅷ.
(Lanthanides and actinides belong to the F region); The valence electron shell is (n-1) d1-9 ns1-2.
Features: ① All are metal elements; ② Total number of valence electrons = sub-family ordinal number;
If the total number of valence electrons is 8, 9, 10, it belongs to group VIII.
Note: there are elements in area D, but they do not conform to the law of (n-1) d1-9 ns1-2, such as 46Pd 4d 10.
4.ds region: It consists of two groups. The valence electron shell of I B and IIB is (n-1) d10ns1or 2.
Features: ① Total number of valence electrons = number of columns; (2) all metal elements; However, D-orbital electrons are fully charged and generally do not participate in the formation of chemical bonds.
5. Zone F: including lanthanides and actinides; Valence electron shell (n-2) F0-14 (n-1) d0-2ns2.
Description: Because the outermost electron number is basically the same, the electron number of (n- 1)d is basically the same, and the electron number of (n-2)f is generally different, so the chemical properties of lanthanides are similar. The chemical properties of actinides are similar.