The outer electronic configuration of Gd (Atomic no. 64) is:

1. 4f³ 5d⁵6d²

2. 4f⁸ 5d¹⁰6d²

3. 4f⁴ 5d⁴6d²

4. 4f⁷ 5d¹6s²

The radius of La³⁺ (at. no. 57) is 1.06 $\stackrel{°}{\mathrm{A}}$ The radius of Lu³⁺ (at.no. 71) might be:

1. 1.06  $\stackrel{°}{\mathrm{A}}$

2. 0.85  $\stackrel{°}{\mathrm{A}}$

3. 1.60  $\stackrel{°}{\mathrm{A}}$

4. 1.40  $\stackrel{°}{\mathrm{A}}$

Which of the following transition metal ions has the lowest density?

1. Copper

2. Nickel

3. Scandium

4. Zinc

Ionic radii are :

1. Inversely proportional to the effective nuclear charge.

2. Inversely proportional to the square of effective nuclear charge.

3. Directly proportional to the effective nuclear charge.

4. Directly proportional to the square of effective nuclear charge.

Which one is a metalloid?

1. Tin

2. Germanium

3. Sulphur

4. Carbon

Zn and Cd do not show variable valency like 'd' block elements due to :

1. Softness

2. Completed 'd' orbital

3. Two electrons in outermost orbit

4. Low m.p.

In the long form of periodic table, the elements having lowest ionization potential are placed in:

1. I group

2. IV group

3. VII group

4. Zero group

Elements with an electronic configuration 1s² 2s²2p⁶  3s²3p⁶3d¹⁰ 4s²4p⁶4d¹⁰ 5s²5p³ belong to the group :

Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states?

1. 3d³,4s²

2. 3d⁵,4s¹

3. 3d⁵,4s²

4. 3d²,4s²

Those in a group that falls under the law of triads include:

1. Cl, Br, I

2. C, N, O

3. Na, K, Rb

4. H, O, N