Question

The number of transition elements in the 1, 2" and 3rd transition series... a) 9 b) 30 c) 10 d) 27

Answer 1

Answer: There are

1. 30 elements for the 1st transition series,
2. 10 elements for the 2nd transition series,
3. 3rd transition series is not listed as one of the given options, but it consists of 14 elements.

Step-by-step explanation:

• 1st transition series: The 1st transition series spans the elements from Scandium (Sc) to Zinc (Zn) in the periodic table.These elements fill the 3d orbitals. Since there are 10 elements in each period of the d-block, the 1st transition series consists of 10 elements.
• 2nd transition series: The 2nd transition series includes the elements from Yttrium (Y) to Cadmium (Cd) in the periodic table. These elements fill the 4d orbitals. Similar to the 1st transition series, there are 10 elements in each period of the d-block, so the 2nd transition series also consists of 10 elements.
• 3rd transition series: The 3rd transition series includes the elements from Lanthanum (La) to Mercury (Hg) in the periodic table. These elements fill the 5d orbitals. In the 5d orbital, there are a total of 10 elements in each period of the d-block. However, the 3rd transition series does not include all 10 elements of the 5d block. It includes 14 elements from Lanthanum (La) to Lutetium (Lu). Therefore, the 3rd transition series consists of 14 elements.