The properties of lithium are similar to those of Mg. This is because

Options

A. both have nearly the same size
B. both have similar electronic configuration
C. both have nearly same charge to size ratio
D. Both are found together in nature

Answer

To understand why the properties of lithium are similar to those of magnesium, we can follow these steps:

### Step 1: Identify the Elements
- We are comparing lithium (Li) and magnesium (Mg).

### Step 2: Understand the Concept of Diagonal Relationship
- A diagonal relationship in the periodic table refers to the similarity in properties between elements that are positioned diagonally from each other. In this case, lithium is in Group 1 (alkali metals), and magnesium is in Group 2 (alkaline earth metals).

### Step 3: Charge and Size Ratio
- Lithium has a charge of +1, while magnesium has a charge of +2.
- The size of lithium is smaller than that of magnesium. The atomic radius of lithium is about 152 pm, and that of magnesium is about 160 pm.

### Step 4: Calculate Charge to Size Ratio
- The charge to size ratio can be understood as the charge of the ion divided by its size (radius).
- For lithium: Charge/Size = +1 / 152 pm
- For magnesium: Charge/Size = +2 / 160 pm
- Although the charges are different, the ratio of charge to size for both elements is similar because the size of magnesium is nearly double that of lithium.

### Step 5: Conclusion
- Because both lithium and magnesium have similar charge to size ratios, they exhibit similar chemical and physical properties. This similarity is the reason for their diagonal relationship.

### Final Answer
The properties of lithium are similar to those of magnesium because both have nearly the same charge to size ratio.

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