An element R forms the highest oxide R₂O₅. R belongs to:

1. 13th  group

2. 15th group

3. 16 th group

4. 2nd group

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

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

1. 4f³ 5d⁵6d²

2. 4f⁸ 5d¹⁰6d²

3. 4f⁴ 5d⁴6d²

4. 4f⁷ 5d¹6s²

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

Elements with an electronic configuration 1s²  2s²  2p⁶  3s²  3p⁶  3d¹⁰ 4s²  4p⁶  4d¹⁰  5s²  5p³ belong to the group :

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

Which among the following options is a nonmetal?

The alkali metals have:

1. highest ionization energy

2. largest atomic radii

3. highest density

4. highest electronegativity

Which of the following statement is correct with respect to the property of elements with increase in atomic number in carbon family.

1. Their metallic character decreases

2. The stability of +2 oxidation state increases

3. Their ionisation energy increases

4. Their atomic size decreases