'Glass' is an example of

Options

A. Pseudo solid
B. True solid
C. Super cooled liquid
D. Both (1) & (3)

Answer

To determine what 'glass' is an example of, we can analyze the properties of glass and the options provided. Here’s a step-by-step solution:

### Step 1: Understand the nature of glass
Glass is known to be an amorphous solid. Unlike crystalline solids, which have a well-defined geometric structure, amorphous solids do not have a long-range order in their atomic arrangement.

**Hint:** Amorphous solids lack a regular arrangement of particles.

### Step 2: Identify the term 'pseudo-solid'
The term 'pseudo-solid' refers to materials that exhibit some properties of solids but do not have a crystalline structure. Since glass is an amorphous solid, it can be classified as a pseudo-solid.

**Hint:** Pseudo-solids are often used to describe materials that behave like solids but lack a crystalline structure.

### Step 3: Understand the term 'supercooled liquid'
The term 'supercooled liquid' refers to a state of matter where a liquid is cooled below its freezing point without solidifying. Glass behaves somewhat like a supercooled liquid because, although it is solid, it flows very slowly over time, similar to how a liquid behaves.

**Hint:** Supercooled liquids can exist below their freezing point without crystallizing.

### Step 4: Analyze the options
Given the definitions:
1. Pseudo-solid
2. Pro-solid (not a standard term in this context)
3. Supercooled liquid
4. Both pseudo-solid and supercooled liquid

Since glass fits both the definitions of pseudo-solid and supercooled liquid, the correct answer is option 4.

**Hint:** Look for options that combine characteristics of the material in question.

### Final Answer
Glass is an example of both pseudo-solid and supercooled liquid (Option 4).