Practice Sheets & eNotes-Periodic Classification of Elements

- Modern periodic table. Modern periodic law and description of Modern periodic table.

- Periodic Laws for classifying elements.
- Brief description of attempts made by different chemists to classify elements- (1) Dobereiner’s triads (2) Newland law of octaves (3) Mendeleev’s periodic law and periodic table (4) Mosley periodic law

- This book contains - Periodic classification of elements.
- Property of elements along the period : Trends in the properties of elements along the period from left to right in the Periodic table.
- Properties like : Valence electrons of the elements, Valency of the elements, Atomic radius of the atoms, Metallic and non-metallic character, Reactivity of the elements

- Property of elements in a group Trend in the properties of elements in a group from top to bottom in the Periodic table.
- Properties like-
  • Valence electrons of the elements and their valency.
  • Size (volume of) of the atoms.
  • Metallic/non-metallic character of the elements.
  • Chemical reactivity of the elements.
  • Gradation of physical properties of the elements.

Periodic classification of elements Worksheet-1

1. Mendeleef's periodic law is based on-

A. Atomic weight                          B. Atomic number

C. Number of neutrons               D. None of these

2. The heaviest atom amongst the following is

A. U                     B. Ra                   C. Pb                   D. Hg