The screening effect of 'd' electrons is :

(a) much less than s-electrons

(b) much more than s-electrons

(c) equal to s-electrons

(d) equal to p-electrons

In a periodic table from I group to VII group electronegativity of elements:

(a) decreases

(b) increases

(c) remains constant

(d) all of these

Match list-I with list II and select the correct answer using codes given below:

1. List-I Ions                                List-II Radius (in pm)

(I) Li⁺                                         (a) 216

(II) Na⁺                                      (b) 195

(III) Br^-                                      (c) 60

(IV) I^-                                        (d) 95

     Codes:

      I   II   III   IV

1.   a   b    d    c

2.   b   c    a    d

3.   c   d    b    a

4.   d   c    b    a 

The screening effect of d-electrons is :

(1) Equal of the p-electrons

(2) Much more than p-electrons

(3) Same as f-electron

(4) Less than p-electrons

Z_eff of Na⁺ and Na⁰ are respectively :-

(1) 1.95 and 1.22

(2) 0.85 and 0.35

(3) 1 and 0.35

(4) 6.85 and 2.2

If Z_eff of element having atomic number 11 is 2.2, then Z_eff of elements having atomic number 12 and atomic number 20 are respectively :-

(1) 2.85, 3.92

(2) 3.92, 2.85

(3) 2.2, 2.2

(4) None of the above

Z_eff of Na⁺ and Na⁰ are respectively :-

(1) 1.95 and 1.22

(2) 0.85 and 0.35

(3) 1 and 0.35

(4) 6.85 and 2.2