Point defects are present in

Options

A. Ionic solids
B. Molecular solids
C. Amorphous solids
D. Liquids

Answer

To solve the question regarding where point defects are present, we can follow these steps:

### Step 1: Understand Point Defects
Point defects refer to irregularities in the crystal lattice where atoms are missing or are in an incorrect position. These defects can significantly affect the properties of the solid.

**Hint:** Remember that point defects are localized disruptions in the crystal structure.

### Step 2: Identify Types of Solids
We need to analyze the options given in the question:
1. Ionic solids
2. Molecular solids
3. Amorphous solids
4. Liquids

**Hint:** Consider the structural characteristics of each type of solid and how they relate to defects.

### Step 3: Analyze Ionic Solids
Ionic solids have a well-defined lattice structure composed of positive and negative ions. They can exhibit various point defects such as vacancies (missing ions), interstitials (extra ions in the lattice), and substitutional defects (where one type of ion is replaced by another).

**Hint:** Ionic solids are known for their ordered structure, which makes them susceptible to point defects.

### Step 4: Analyze Molecular Solids
Molecular solids are held together by intermolecular forces rather than ionic or covalent bonds. While they can have defects, they are not typically classified as point defects in the same way as ionic solids.

**Hint:** Focus on how the bonding in molecular solids differs from ionic solids.

### Step 5: Analyze Amorphous Solids
Amorphous solids lack a long-range order in their structure. They do not have a defined lattice, which makes the concept of point defects less applicable.

**Hint:** Consider the lack of a crystalline structure in amorphous solids.

### Step 6: Analyze Liquids
Liquids do not have a fixed structure like solids do. They are fluid and do not possess a crystalline lattice, hence point defects are not relevant in this context.

**Hint:** Think about the properties of liquids compared to solids.

### Conclusion
After analyzing all the options, we conclude that point defects are primarily present in **ionic solids**. Therefore, the correct answer is option 1.

**Final Answer:** Point defects are present in ionic solids.