English
Русский
Oʼzbek
Subjects
News and articles
About us
Career
Contacts
Profile
Watch history
My library
Notifications
Logout
Русский
Oʼzbek
Online Mektep
Authorization
Home
Subjects
School Subjects
Main
Subjects
School Subjects
Chemistry
Upper Secondary
5. Periodic table
5. Periodic table
18. The periodic table of the elements
19. The trends in the properties of the elements in Period
20. Periodic trends in the chemical properties of elements
21. s-Block elements
22. Chemical properties of s-block elements
23. Elements of Group 17
24. Reactions of halogens