Full Chapter Notes
Short Question
MCQ’s with Exercise
Class 12th Chemistry Chapter – “S-Block Elements” focuses on the properties, reactions, and significance of the s-block elements in the periodic table. Here’s a brief overview:
- Definition and Composition: The s-block elements include Group 1 (alkali metals) and Group 2 (alkaline earth metals). They are characterized by the filling of the s orbital in their electronic configuration.
- General Properties:
- Alkali Metals (Group 1): Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr). They are soft, highly reactive, and have low melting and boiling points. They readily lose one electron to form +1 ions.
- Alkaline Earth Metals (Group 2): Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra). They are harder than alkali metals, less reactive, and form +2 ions.
- Reactivity: Both groups are highly reactive, with alkali metals reacting vigorously with water to form hydroxides and hydrogen gas. Alkaline earth metals also react with water, though less vigorously.
- Trends in Properties: Discusses trends in atomic size, ionization energy, and electronegativity within the groups, including how these trends influence the reactivity of the elements.
- Compounds: Overview of common compounds formed by s-block elements, such as hydroxides, carbonates, and nitrates, and their applications in various fields.
- Biological Importance: Highlights the role of certain s-block elements in biological systems, such as sodium and potassium in cellular functions.
This chapter provides a comprehensive understanding of the s-block elements, their properties, reactions, and significance in chemistry and everyday life.