Alkali metals contain

Options

A. 7 valence electrons
B. 1 valence electron
C. 4 valence electrons
D. 2 valence electrons.

Explanation

To answer the question "Alkali metals contain," we need to analyze the properties of alkali metals and their electronic configurations. Here is a step-by-step solution:

### Step 1: Identify Alkali Metals
Alkali metals are located in Group 1 of the periodic table. The alkali metals include:
- Hydrogen (H)
- Lithium (Li)
- Sodium (Na)
- Potassium (K)
- Rubidium (Rb)
- Cesium (Cs)
- Francium (Fr)

### Step 2: Determine the Electronic Configuration
Next, we need to look at the electronic configurations of these elements to find out how many valence electrons they have. The electronic configurations for the alkali metals are as follows:
- Hydrogen (H): 1s¹
- 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
- Francium (Fr): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶ 5s² 5p⁶ 6s² 6p⁶ 7s¹

### Step 3: Identify Valence Electrons
From the electronic configurations, we can see that all alkali metals have one electron in their outermost shell (valence shell). This means:
- Valence electrons for all alkali metals = 1

### Step 4: Conclusion
Based on the above analysis, we can conclude that alkali metals contain **1 valence electron**.

### Final Answer
The correct option is **1 valence electron**.

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