The group of elements in which the last electron is present the anti-penultimate shell of atom called

Options

A. f-block elements
B. d-block elements
C. p-block elements
D. s-block elements

Answer

To solve the question, we need to identify the group of elements where the last electron is added to the anti-penultimate shell of the atom. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the term "anti-penultimate shell"
The anti-penultimate shell refers to the shell that is two levels below the outermost shell. In terms of electron configuration, it typically corresponds to the f-orbitals when we are discussing the filling of electron shells.

**Hint:** Remember that the anti-penultimate shell is two shells below the outermost shell.

### Step 2: Identify the relevant orbitals
The last electron entering the anti-penultimate shell would be filling the f-orbitals. Specifically, these are the 4f and 5f orbitals.

**Hint:** Focus on the f-orbitals when considering the anti-penultimate shell.

### Step 3: Determine the group of elements
Elements that have their last electron entering the 4f or 5f orbitals are classified as f-block elements. These elements are also known as inner transition elements.

**Hint:** Recall that f-block elements include lanthanides and actinides.

### Step 4: Review the options provided
The options given are:
1. F block elements
2. D block elements
3. P block elements
4. S block elements

Since we established that the last electron in the anti-penultimate shell corresponds to the f-orbitals, the correct answer is:

**Answer:** Option 1 - F block elements

### Final Answer
The group of elements in which the last electron is present in the anti-penultimate shell of the atom is called **F block elements**.

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