Mention the degree of freedom for diatomic gas molecules without vibration.

Options

A. 2
B. 3
C. 5
D. 7

Answer

To determine the degree of freedom for diatomic gas molecules without vibration, we can follow these steps:

### Step 1: Understand the concept of degrees of freedom
Degrees of freedom refer to the number of independent ways in which a molecule can move or store energy. For gases, these typically include translational, rotational, and vibrational motions.

### Step 2: Identify the types of motion for diatomic gases
For diatomic gas molecules, the types of motion are:
- **Translational motion**: Movement in three-dimensional space.
- **Rotational motion**: Rotation around two axes (the third axis is not counted as it does not contribute to energy in the same way due to the symmetry of diatomic molecules).
- **Vibrational motion**: This involves the stretching and compressing of the bond between the two atoms.

### Step 3: Count the degrees of freedom
For a diatomic gas without considering vibrational motion:
- **Translational degrees of freedom**: 3 (movement in x, y, and z directions)
- **Rotational degrees of freedom**: 2 (rotation around two axes)

Thus, the total degrees of freedom for diatomic gas molecules without vibration is:
\[ \text{Total degrees of freedom} = \text{Translational} + \text{Rotational} = 3 + 2 = 5 \]

### Step 4: Conclusion
Therefore, the degree of freedom for diatomic gas molecules without vibration is **5**.

---