The electronic configuration of the most electropositive element is :

1. [He]2s¹

2. [Xe]6s¹

3. [He]2s²

4. [Xe]6s²

Which one of the following is an amphoteric oxide?

1. SO₂

2. B₂O₃

3. ZnO

4. Na₂O

Transition elements exhibit variable oxidation states because they release electrons from the following orbits:

1. ns and np orbits

2. (n-1)d and ns orbits

3. (n-1)d orbits

4. ns orbits

Elements of group IB  is called as:

Element that has the greatest tendency to lose an electron is :

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

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.