Let's analyze the elements to determine which one is the least similar to magnesium (Mg).
1. Magnesium (Mg):
- Magnesium is an alkaline earth metal.
- It is located in Group 2 of the periodic table.
2. Comparing the given elements:
- A. Beryllium (Be):
- Beryllium is also an alkaline earth metal.
- It is located in Group 2, same as magnesium.
- B. Strontium (Sr):
- Strontium is an alkaline earth metal.
- It is located in Group 2, same as magnesium.
- C. Calcium (Ca):
- Calcium is an alkaline earth metal.
- It is located in Group 2, same as magnesium.
- D. Sodium (Na):
- Sodium is an alkali metal.
- It is located in Group 1, which is different from magnesium's group.
3. Conclusion:
- Elements in the same group have similar properties due to their similar valence electron configurations.
- Be, Sr, and Ca are all in Group 2, making their properties similar to those of Mg.
- Na, on the other hand, is in Group 1, meaning it has different properties compared to the Group 2 elements.
Thus, the least similar element to magnesium (Mg) is sodium (Na), which corresponds to option D.
Therefore, the answer is D.
