The Periodic Table of Elements — العلوم الصف الأول الإعدادي لغات

الدرس الثاني

الدرس ده من وحدة «The Matter» فى مادة العلوم لـالصف الأول الإعدادي لغات على منصة دروسات.

الدرس متاح بالاشتراك: ترم كامل أو المادة لوحدها.

ملخص الدرس

This lesson covers the development of the periodic table, from Mendeleev's original arrangement by atomic mass to the modern table organized by atomic number. It explains the structure of the modern periodic table in terms of periods and groups, and relates an element's position to its electron configuration. The lesson also discusses valency, the periodic trends in atomic radius, melting and boiling points, and the chemical activity of different groups.

هتتعلم إيه فى الدرس ده

• The periodic table is a system for classifying elements based on their properties and electron configurations.
• The modern periodic table is arranged by increasing atomic number and consists of 7 periods and 18 groups.
• The period number of an element equals the number of occupied energy levels in its atom.
• The group number of an element equals the number of valence electrons in its atom (for groups 1A-7A).
• Elements in the same group exhibit similar chemical properties, and valency is determined by the number of valence electrons.