Read the periodic table of elements at the end of the textbook carefully and tell me what regularity you see from it.

1. In the same period, the metallicity of elements decreases from left to right, and the nonmetal increases from left to right.

2. In the same family, the metallicity of elements increases from top to bottom, and the nonmetal decreases from top to bottom;

3. In the same period, the highest positive oxidation number of elements increases from left to right (except those without positive valence), and the lowest negative oxidation number increases gradually from left to right;

4. The elements of the same family are similar in nature.

5. In the main group elements of the same period, the atomic radius decreases with the increase of atomic number.

6. In the same family, the atomic radius increases with the increase of atomic number. If the electron configuration of particles is the same, the radius of anion is larger than that of cation, and the radius decreases with the increase of charge number, and so on.