The elements of same group of the periodic table have

Options

A. 1. Atomic number
B. 2. Electronic configuration
C. 3. Atomic weight
D. 4. Number of electrons in the valence shell

Answer

To answer the question regarding the properties of elements in the same group of the periodic table, we will analyze the characteristics of these elements step by step.

### Step 1: Understanding Groups in the Periodic Table
The periodic table is organized into columns known as groups. Elements in the same group share similar chemical properties due to their similar electronic configurations.

**Hint:** Look at the arrangement of elements in the periodic table and identify the groups.

### Step 2: Identifying Valence Electrons
Elements in the same group have the same number of valence electrons. For example, Group 1 elements (alkali metals) like lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs) all have one electron in their outermost shell.

**Hint:** Recall the concept of valence electrons and how they determine the chemical behavior of elements.

### Step 3: Analyzing Electronic Configurations
For Group 1:
- Lithium (Li): 1s² 2s¹
- Sodium (Na): 1s² 2s² 2p⁶ 3s¹
- Potassium (K): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
- Rubidium (Rb): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s¹
- Cesium (Cs): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁶ 6s¹

From these configurations, we can see that all these elements have one electron in their outermost shell (the valence shell).

**Hint:** Compare the electronic configurations of the elements in the same group to identify the commonality.

### Step 4: Conclusion
Since all elements in the same group have the same number of valence electrons, we can conclude that the elements of the same group have similar chemical properties and reactivity.

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