The last member in each period of the periodic table is

Options

A. An inert gas element
B. A transition element
C. A halogen
D. An alkali metal

Answer

To solve the question regarding the last member in each period of the periodic table, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Periodic Table**:
The periodic table is organized into periods (rows) and groups (columns). Each period corresponds to the filling of a particular electron shell.

2. **Identify the Last Member of Each Period**:
The last element in each period corresponds to the element that completes the filling of the outermost electron shell.

3. **Recognize the Group of the Last Members**:
The last member of each period belongs to Group 18, which is known as the noble gases or inert gases. These elements have a complete valence shell, making them stable and unreactive.

4. **List the Noble Gases**:
The noble gases include:
- Helium (He) - Period 1
- Neon (Ne) - Period 2
- Argon (Ar) - Period 3
- Krypton (Kr) - Period 4
- Xenon (Xe) - Period 5
- Radon (Rn) - Period 6

5. **Conclude the Answer**:
Since the last member of each period is a noble gas, the correct answer to the question is that the last member in each period of the periodic table is an inert gas element.

### Final Answer:
The last member in each period of the periodic table is an **inert gas element**.

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