Match the items given in Column I with the items given in Column II.
`{:( " Column I " , " Column II"),( "(i) Mg in solid state" , " (a) p -type semiconductor"),("(ii)" MgCl_(2) " in molten state" , "(b) n-type semiconductor"),(" (iii) Silicon with phosphorus" , "(c) electrolytic conductors ") , (" (iv) Geranium with boron " , " (d) Electronic conductors " ):}`

Answer

To solve the matching question between Column I and Column II, we will analyze each item in Column I and determine its corresponding match in Column II based on the properties of the substances mentioned.

### Step-by-Step Solution:

1. **(i) Mg in solid state**:
- Magnesium (Mg) in solid state behaves as an electronic conductor. This is due to the presence of free electrons that can move through the solid structure, allowing it to conduct electricity.
- **Match**: (i) Mg in solid state → (d) Electronic conductors

2. **(ii) MgCl₂ in molten state**:
- Magnesium chloride (MgCl₂) when melted becomes an electrolyte. In the molten state, it dissociates into Mg²⁺ and Cl⁻ ions, allowing it to conduct electricity through ionic movement.
- **Match**: (ii) MgCl₂ in molten state → (c) Electrolytic conductors

3. **(iii) Silicon with phosphorus**:
- When silicon is doped with phosphorus, it creates an n-type semiconductor. Phosphorus is a pentavalent element, which donates extra electrons to the silicon lattice, enhancing its conductivity.
- **Match**: (iii) Silicon with phosphorus → (b) n-type semiconductor

4. **(iv) Germanium with boron**:
- Doping germanium with boron results in a p-type semiconductor. Boron is a trivalent element, which creates "holes" in the germanium lattice, allowing for positive charge carriers.
- **Match**: (iv) Germanium with boron → (a) p-type semiconductor

### Final Matches:
- (i) Mg in solid state → (d) Electronic conductors
- (ii) MgCl₂ in molten state → (c) Electrolytic conductors
- (iii) Silicon with phosphorus → (b) n-type semiconductor
- (iv) Germanium with boron → (a) p-type semiconductor