ICSE BOARD THE PERIODIC TABLE - PART I CHEMISTRY CLASS IX

1. ICSE
Class 9
Chemistry - Chapter 5
The periodic table
(PART – I)

2. INTRODUCTION

5. 5.1 Reasons for the classification of
elements

9. 5.2 Dobereiner’s Triad

20. 5.3 Newlan’ds law of octaves

25. So according to the Newland’s Law of
octaves when elements are arranged in
order of increasing atomic masses, the
properties of the 8th elements are a
repetition of properties of 1st elements.

26. Issues with Newland’s law of
octaves
1st – Only valid till Ca
2nd - Newland’s assumed that there
are only 56 elements in nature
3rd – Puts 2 elements in 1 slot

33. 5.4 Mendeleev’s periodic table

36. 1 - Atomic mass
- Mass of 1 atom of an
element
- Unit : Atomic Mass
Unit (amu)
- H = 1 amu
- C = 12 amu

37. 2 - Physical properties
Density
Melting Point of an
element
Boiling Point of an
element

38. 3 - Chemical properties.
How an element react with
other element.
React with hydrogen and
oxygen.

39. Example
Sodium
(Na)
Potassium
(K)
R
NaH KH RH
N𝑎2O 𝐾2O 𝑅2O
Mendeleev used the formulae of oxide and hydrides

45. Inert and Noble gases
• Unreactive nature
• Low concentration
in atmosphere

47. LIMITATIONS

52. READ