`{:("Column I (Defect)", " Column II (Effect)"),("(A) Schottky defect", "(p) Crystal becomes coloured"),("(B) Doping silicon with aluminium" , "(q) n-type semiconductor is formed"),("(C) Doping silicon with arsenic" , "(r) p-type semiconductor is formed "),( "(D) Heating NaCl crystal in presence of sodium vapour" , (s) "Density of the crystal decreases"):}`

Options

A. A-s, B-q, C-r, D-p
B. A-q,B-p, C-r, D-s
C. A-q,B-s,C-q,D-p
D. A-s, B-r, C-q, D-p

Answer

To solve the question, we need to match the defects in Column I with their corresponding effects in Column II. Let's analyze each defect one by one.

### Step-by-Step Solution:

1. **Schottky Defect (A)**:
- A Schottky defect occurs when equal numbers of cations and anions are missing from the crystal lattice, creating vacancies.
- This results in a decrease in the density of the crystal because the total number of ions decreases.
- **Effect**: The density of the crystal decreases (s).
- **Match**: A - s

2. **Doping Silicon with Aluminium (B)**:
- Doping silicon with aluminium introduces an element that has three valence electrons (Aluminium).
- This creates "holes" in the silicon lattice, leading to a deficiency of electrons.
- This type of doping results in the formation of a p-type semiconductor.
- **Effect**: p-type semiconductor is formed (r).
- **Match**: B - r

3. **Doping Silicon with Arsenic (C)**:
- Doping silicon with arsenic introduces an element that has five valence electrons (Arsenic).
- This adds extra electrons to the silicon lattice, resulting in an n-type semiconductor.
- **Effect**: n-type semiconductor is formed (q).
- **Match**: C - q

4. **Heating NaCl Crystal in Presence of Sodium Vapour (D)**:
- When NaCl is heated in the presence of sodium vapour, it can lead to the formation of color centers, which gives the crystal a yellow color.
- **Effect**: The crystal becomes coloured (p).
- **Match**: D - p

### Final Matches:
- A - s (Schottky defect leads to a decrease in density)
- B - r (Doping with aluminium forms a p-type semiconductor)
- C - q (Doping with arsenic forms an n-type semiconductor)
- D - p (Heating NaCl in sodium vapour causes coloration)

### Summary of Matches:
- A - s
- B - r
- C - q
- D - p