The diagonal partner of B is

Options

A. Li
B. Al
C. Si
D. Mg.

Answer

To determine the diagonal partner of boron, we can follow these steps:

### Step 1: Understand the Concept of Diagonal Relationship
Diagonal relationship refers to the similarity in properties between certain pairs of elements in the periodic table that are positioned diagonally to each other. This occurs due to the balance of charge and size between the elements.

### Step 2: Identify the Position of Boron
Boron (B) is located in Group 13 (IIIA) and Period 2 of the periodic table.

### Step 3: Locate the Diagonal Element
To find the diagonal partner of boron, we look at the element that is located diagonally below boron in the periodic table. This would be the element in Group 13 (IIIA) of Period 3.

### Step 4: Identify the Element Below Boron
The element directly below boron in Group 13 is aluminum (Al). However, we need to find the diagonal partner, which is located in Group 14 (IVA) of Period 3.

### Step 5: Determine the Diagonal Partner
The element that is diagonally positioned to boron (B) is silicon (Si), which is in Group 14 (IVA) and Period 3.

### Conclusion
Thus, the diagonal partner of boron is silicon (Si).