The elements of same group of the periodic table have

Options

A. Same number of protons
B. Same valence shell
C. Same valence electrons
D. Same electrons affinity

Answer

To solve the question, "The elements of the same group of the periodic table have," we will analyze the characteristics of elements within the same group.

### Step-by-Step Solution:

1. **Understanding Groups in the Periodic Table**:
- Elements in the periodic table are arranged in vertical columns called groups. Each group contains elements that share similar chemical properties.

2. **Identifying Valence Electrons**:
- The key characteristic of elements in the same group is that they have the same number of valence electrons. For example, all elements in Group 1 (alkali metals) have one valence electron.

3. **Examining Other Options**:
- **Same Number of Protons**: This is incorrect because elements in the same group have different atomic numbers, which means they have different numbers of protons.
- **Same Valence Shell**: While elements in the same group have similar valence electron configurations, the principal energy levels (or shells) can differ. For example, lithium (Li) has electrons in the 2nd shell, while sodium (Na) has electrons in the 3rd shell.
- **Same Electron Affinity**: Electron affinity can vary among elements in the same group due to differences in atomic size and nuclear charge, so this is also incorrect.

4. **Conclusion**:
- Therefore, the correct answer is that elements of the same group have the **same number of valence electrons**.

### Final Answer:
The elements of the same group of the periodic table have the same number of valence electrons.

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