CBSE - Periodic Classification of Elements

1 Periodic Classification of Elements 

Number of valence electrons in Magnesium is–

(1) 12
(2) 10
(3) 8
(4) 2

2 Periodic Classification of Elements 

Which of the following is the correct order of relative sizes ? 

(1) I^– > I⁺ > I 
(2) I^– > I > I⁺
(3) I > I⁺ > I^–
(4) I⁺ > I^– > I

3 Periodic Classification of Elements 

The element E, F, G, H and I have atomic number 9, 11, 17, 12 and 13 respectively. The pair of elements which belongs to the same group of the periodic table is 

(1) F and H 
(2) E and G 
(3) H and I 
(4) E and F

4 Periodic Classification of Elements 

On moving from left to right in a period of the periodic table, the atomic number of elements increases. What happens to the size of atoms of elements on moving from left to right in a period ?

(1) Increases
(2) Decreases
(3) Remains the same
(4) First increaeses then decreases

5 Periodic Classification of Elements 

An element , X has electronic configuration 2, 8, 4. Which of the following is not appropriate for X?

(1) It belong to group 14 and 3rd period of periodic table
(2) It is a chalcogen
(3) Its oxide is a solid
(4) It have can maximum covalency of six
 

6 Periodic Classification of Elements 

All the elements in a group have the

(1) Same valency
(2) Different valency
(3) Variable valency
(4) None of these