Which of the following has maximum atomic size? (a) K (b) Ca (c) Al (d) P The law of octaves was proposed by (a) Newland (b) Doberiener (c) Lother Meyer (d) Mendleeve The number of periods in the long form of the periodic table is (a) 6 (b) 7 (c) 10 (d) 18 Which of the following elements has maximum metallic character? (a) Li (b) N (c) Na (d) P Which of the following is the most reactive halogen? (a) F (b) Cl (c) Br (d) I Why do elements in a group show same valency? Why are the members of group 1 known as alkali metals? How does metallic character of the elements vary (i) In a group (ii) In a period? Name the other elements which belong to the same family as (i) Calcium (ii) Carbon. How would tendency to gain electrons change as you go down in a group? Two elements X and Y belong to Group 1 and Group 2 respectively in the same period. Compare them with respect to: (a) The number of valence electrons (b) Valency (c) metallic character (d) Size of the atoms (e) Formula of their oxides and chlorides. The following table shows the position of six elements A, B, C, D, E and F in the period table. Groups Periods 2 3 1 2 A D E 3 to 12 13 14 15 16 B 17 18 C F
3. 4. 5. 6. 7. 8. 9. 10. 11.
(1) (1) (1) (2) (2) (2) (2) (3) (3)
Using the table answer the following (a) Which element will form only covalent compounds? (b) Which element is a metal with valency 2. (c) Which clement is a non-metal with valency 3. (d) Out of D and E which has bigger atomic radius and why? (e) Write a common name for the family of elements C and F
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