Third Transition Series (Lanthanum to Mercury)

What is the atomic number of lanthanum?

Which of the following elements has an atomic number of 72?

What is the general electronic configuration of d-block elements?

Which of the following elements does not exhibit variable oxidation states?

What is the name of the series that corresponds to the filling of 6d orbitals?

How many elements are present in the fourth transition series?

Which of the following transition metals exhibits common oxidation state?

What is the last electron in transition elements located in?

What is the general electronic configuration of d-block elements?

Which element has the atomic number 21 and starts the first transition series?

What is the characteristic feature of d-block elements?

How many transition series are there in the d-block?

Which element has the electronic configuration [Ar] 3d10 4s1?

What is the name of the series that corresponds to the filling of 4d orbitals?

Which element has the atomic number 48 and is in the second transition series?

What is the characteristic of transition metals?

Transition Elements

Elements between the S-block and the P-block are called transition elements or d-block elements.
They show transitional properties between s and p-block elements.
They have partially filled d-orbitals, hence called d-block elements.

General Electronic Configuration

The general electronic configuration of d-block elements is (n-1)d1-10ns1-2.

Classification of Transition Series

D-block elements are classified into four transition series corresponding to the filling of 3d, 4d, 5d, and 6d orbitals.

First Transition Series (3d Series)

It starts from scandium (atomic number 21) and includes 10 elements till zinc (atomic number 30).
Electronic configurations of elements in this series are:
- Scandium: [Ar] 3d1 4s2
- Titanium: [Ar] 3d2 4s2
- ... (all the way to zinc)

Second Transition Series (4d Series)

It starts from yttrium (atomic number 39) and includes 10 elements till cadmium (atomic number 48).
Electronic configurations of elements in this series are:
- Yttrium: [Kr] 4d1 5s2
- Zirconium: [Kr] 4d2 5s2
- ... (all the way to cadmium)

Third Transition Series (5d Series)

It starts from lanthanum (atomic number 57) and includes 9 elements till mercury (atomic number 80).
Electronic configurations of elements in this series are:
- Lanthanum: [Xe] 5d1 6s2
- Hafnium: [Xe] 4f14 5d2 6s2
- ... (all the way to mercury)

Fourth Transition Series (6d Series)

It contains only 3 elements: actinium (atomic number 89), and two elements with atomic numbers 104 and 105.
This series is incomplete.

Characteristics of Transition Metals

Transition metals except Zn, Cd, and Hg exhibit several physical and chemical properties.
They have variable oxidation states due to the participation of both ns and (n-1)d electrons in bonding.

This quiz covers the elements of the third transition series, from lanthanum to mercury, including their atomic numbers, symbols, and electronic configurations.