On completion of this lesson, students should be able to:
Valence electrons, valency, atomic size, ionization energy, metallic character, electron-positivity, electron-negativity and reactivity are the characteristics of groups. This note describes about variations in different properties of a group in a periodic table.
The number of valence electrons in a period increase from 1 to 8 on going from left to right in a period. This note describes about variation in various properties of a period in a periodic table.
Mendeleev's periodic law states that "All the physical and chemical properties of the elements are the periodic function of their increasing atomic weight". This note has information about Mendeleev's Periodic Table, its advantages and disadvantages are also discussed.
Modern periodic law states, "All the physical and chemical properties of an element are the periodic functions of their increasing atomic number". This note has detail information about modern periodic table, its advantages characteristics and components.
The reactivity of an element belonging to metals increase on moving from top to bottom in a group of the periodic table. While moving from top to bottom in a group of the periodic table, the reactivity of non- metals decreases.