How many distinct orbital blocks are represented in the modern periodic table?

• A. Four
• B. Three
• C. Five
• D. Two

Answer: (A)

Verified step by step guidance

1. Understand that the modern periodic table is divided into blocks based on the type of atomic orbitals that are being filled with electrons in the elements' ground states.
2. Identify the four main types of atomic orbitals involved: s, p, d, and f orbitals. Each corresponds to a block in the periodic table.
3. Recall that the s-block includes groups 1 and 2 (alkali and alkaline earth metals), the p-block includes groups 13 to 18, the d-block corresponds to the transition metals (groups 3 to 12), and the f-block contains the lanthanides and actinides.
4. Recognize that these four blocks represent the distinct orbital types where electrons are added as you move across the periodic table.
5. Conclude that the number of distinct orbital blocks represented in the modern periodic table is four.