Elements have been classified as as s-,p-, d- and f-block elements of the basis of the types of orbital which receives the last electron. Are there any exceptions to this generalization ? Comment.

Explanation

To answer the question regarding the classification of elements into s-, p-, d-, and f-blocks based on the type of orbital that receives the last electron, we will follow these steps:

### Step 1: Understanding the Classification
Elements are classified into four blocks (s, p, d, and f) based on the type of atomic orbital that is being filled with the last electron.

- **s-block**: Groups 1 and 2 of the periodic table, where the last electron enters an s orbital.
- **p-block**: Groups 13 to 18, where the last electron enters a p orbital.
- **d-block**: Transition metals, where the last electron enters a d orbital.
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