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  2s²  2p⁶  3s²  3p⁶  3d¹⁰ 4s²  4p⁶  4d¹⁰  5s²  5p³ 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

 All the non-metals in the long form of the periodic table are placed under:

1. s-Block

2. p-Block

3. f-Block

4. d-Block

General electronic configuration of the transition elements is given by:

1. ns²nd^1-10

2. ns²np⁶nd^1-10

3. (n-1)d^1-10np⁶

4. (n-1)d^1-10ns^1-2

The statement that is incorrect for the periodic classification of elements is:

The ions O^2-, F^-, Na⁺, Mg^2+, and Al³⁺ are isoelectronic. Their ionic radii show [2003]

1. an increase from O^2- to F^- and then decrease from Na⁺ to Al³⁺

2. a decrease from O^2- to F^- and then increase from Na⁺ to Al³⁺

3. a significant increase from O^2- to Al³⁺

4. a significant decrease from O^2- to Al³⁺

An example of metalloid elements in the periodic table is: