Understanding Atomic Number 56
Atomic number 56 corresponds to the element Barium (Ba). To determine its block in the periodic table, we need to understand the structure of the periodic table and how elements are categorized into blocks.
Periodic Table Blocks
The periodic table is divided into four main blocks based on the electron configuration of the elements:
- s-block: Groups 1 and 2, plus Helium. These elements have their outermost electrons in s orbitals.
- p-block: Groups 13 to 18. The outermost electrons are found in p orbitals.
- d-block: Transition metals, which are found in groups 3 to 12. Their outermost electrons are in d orbitals.
- f-block: Lanthanides and Actinides, where the outermost electrons are in f orbitals.
Position of Barium in the Periodic Table
- Barium (Ba) is located in Group 2 of the periodic table.
- It is part of the alkaline earth metals, which are characterized by having two electrons in their outermost shell.
- The electron configuration of Barium is [Xe] 6s², indicating that the outermost electrons are in the 6s orbital.
Conclusion
Given that Barium has its outermost electrons in the s orbital, it is classified as belonging to the s-block of the periodic table. Thus, the correct answer to the question regarding the block of the element with atomic number 56 is option 'D' (s-block).