Class Eleventh Chemistry: Classification of Elements and Periodicity in Properties

Introduction

• In this lesson, we will study the classification of elements and their properties.
• Everything will be crystal clear after viewing the lesson.

Importance of the Topic

• It is crucial to know how chemistry books at home are organized.
• We will discuss many elements and their properties.

History and Development

• For the first time, systematic classification was made by Banner with 90 elements.
• Newland created a table with 106 elements.
  • In this table, elements were arranged in increasing order of atomic mass.
• At one point, chemical properties were understood through 63 elements.
• A classification based on atomic number was developed with 90.

Modern Periodic Table

• The modern periodic table was developed based on modern physics and chemical properties.
• It is crucial to arrange elements according to atomic number.
  • At regular intervals, the properties of elements repeat.

Types of Periodic Table

• The long-form periodic table is the most commonly used.
• Only 2 elements are in the first period: Hydrogen, Helium.
• The second, third, fourth,... periods have 8, 18, and 32 elements respectively.

Trends in Atomic Properties

• Decreases: Atomic radius (left to right)
• Increases: Atomic radius (top to bottom)
• Paying attention to electronic configuration is essential.

Electronic and Ionization Energy

• Ionization Energy: The amount of energy required to arrange electrons.
• Ionization energy directly depends on electronic configuration.
  • Increases from top to bottom in a group.
  • Decreases from left to right in a period.

Differences between Non-metals and Metals

• Non-metals: Do not maintain shape at room temperature, while metals remain solid.
• Metals generally release electrons easily.
• Any element that can react based on its electronegativity.

Conclusion

• By the end of this video, all your doubts will be cleared.
• Write if needed, in the next video we will discuss a new topic.

Notes

• These notes will help enhance your insights.
• Subscribe and enjoy learning!