Salient features of long form periodic table

chemistry
class 9
Salient features of long form periodic table

1. CHEMISTRY 9 SALIENT FEATURES OF LONG FORM PERIODIC TABLE

2. PERIODIC TABLE The periodic table is a tabular arrangement of the chemical elements . It is organized in order of increasing atomic number.

3. SALIENT FEATURES: 1 The long form of modern periodic table consists of seven rows called periods

4. 2 First period consists of only two elements. Second and third periods consist of 8 elements each. Fourth and fifth periods consist of 18 elements each. Sixth period has 32 elements while seventh period has 23 elements and is incomplete.

5. 3 Elements of a period show different properties.

6. 4 There are 18 vertical columns in the periodic table numbered 1 to 18 from left to right, which are called groups.

7. 5 The elements of a group show similar chemical properties.

8. 6 Elements are classified into four blocks depending upon the type of the subshell which gets the last electron.

9. BLOCKS

10. BLOCKS On the basis of completion of a particular subshell, elements with similar subshell electronic configuration are referred as a block of elements.

11. There are four blocks s-block p-block d-block f-block

12. s-block s - block elements  are the  elements  found in Group 1 and Group 2 on the periodic table. Valence electron of s-block elements are found in ‘s’ subshell.

13. p-block The  p - block  is the area of the periodic table containing columns 3A to column 8A (columns 13-18), not including helium.  p - block elements , have valence electrons in the  p  orbital.

14. d-block d-block elements  constitute the periods 4,5 and6 of the modern periodic table. The valence electrons of these  elements  fall under the  d  orbital.  d-block elements  are also referred to as transition  elements  or transition metals.

15. f-block The  f block elements  are the lanthanides and actinides and are called the inner transition elements. Their valance electrons are found in f orbital