1. How many elements are there in 6th period of periodic table?

2. The electronic configuration of halogen is

3. The order of increasing sizes of atomic radii among the elements O, S, Se and As is :

4. On the Paulings electro negativity scale the element next to F is

5. Which of the following oxides is amphoteric in character?

6. Why the size of an anion is larger than the parent atom?

7. Increasing order of electro negativity is

8. The electronic configuration of an element is 1s², 2s² 2p⁶, 3s² 3p³. What is the atomic number of the element which is just below the above element in the periodic table

9. The element with atomic number 35 belongs to

10. The reduction in atomic size with increase in atomic number is a characteristic of elements of-

11. The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups. Its reason is:

12. Arrange S, O and Se in ascending order of electron affinity

13. Which of the following properties generally decreases along a period?

14. Diagonal relationship is shown by

15. Which of the following is not an actinoid?

16. Periodic classification of elements is used to examine the

17. Correct order of ionization enthalpies is

18. The statement that is not correct for periodic classification of elements is:

19. The electron affinity for the inert gases is –

20. The element californium belongs to a family of :