The most reactive elements is

Options

A. `Be`
B. `Ba`
C. `Sr`
D. `Mg`

Answer

To determine the most reactive element among the alkaline earth metals, we need to analyze the properties of these metals and their reactivity trends. Here’s a step-by-step solution:

### Step 1: Identify the Alkaline Earth Metals
The alkaline earth metals are located in Group 2 of the periodic table. They include:
- Beryllium (Be)
- Magnesium (Mg)
- Calcium (Ca)
- Strontium (Sr)
- Barium (Ba)
- Radium (Ra)

### Step 2: Understand Reactivity Trends
Reactivity in metals generally increases as you move down a group in the periodic table. This is because:
- The atomic size increases, leading to a greater distance between the nucleus and the outermost electrons.
- The outer electrons are less tightly held due to increased shielding from inner electrons.

### Step 3: Analyze the Ionization Energy
The reactivity of alkaline earth metals is related to their ability to lose their two valence electrons to achieve a stable noble gas configuration. The lower the ionization energy, the more reactive the metal.

### Step 4: Compare the Elements
- Beryllium (Be) has a higher ionization energy compared to other alkaline earth metals, making it less reactive.
- Magnesium (Mg) has a lower ionization energy than beryllium and is more reactive.
- Calcium (Ca), Strontium (Sr), and Barium (Ba) have progressively lower ionization energies and thus are more reactive than magnesium and beryllium.

### Step 5: Conclusion
Among the alkaline earth metals, as we move down the group, the reactivity increases. Therefore, the most reactive element in the alkaline earth metals is **Barium (Ba)**, not Beryllium (Be) as incorrectly stated in the video.

### Final Answer
The most reactive element among the alkaline earth metals is **Barium (Ba)**.

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