The molecules of a gas are in constant (i) _______ motion . They move in (ii) ________ lines until they collide with another molecule . The collisions are perfectly (iii) _________ in nature . A real gas behaves as an ideal gas at (iv) _________ temperature and (v) _________ pressure .

Options

A. `{:(" (i)"," (ii)"," (iii)","(iv)","(v)"),("random","vertical","straight","high","low"):}`
B. `{:(" (i)"," (ii)"," (iii)","(iv)","(v)"),("straight","random","elastic","low","high"):}`
C. `{:(" (i)"," (ii)"," (iii)","(iv)","(v)"),("random","straight","elastic","high","low"):}`
D. `{:(" (i)"," (ii)"," (iii)","(iv)","(v)"),("ideal","round","elastic","low","high"):}`

Answer

To solve the question, we need to fill in the blanks with the appropriate terms based on the principles of the kinetic theory of gases. Let's go through it step by step.

1. **Understanding the motion of gas molecules**: The first blank asks about the type of motion gas molecules exhibit. According to the kinetic theory of gases, gas molecules are in constant motion. The correct term to fill in the first blank is "random."

**Hint**: Think about how gas molecules behave in a container; they move in all directions.

2. **Direction of motion**: The second blank requires us to describe the path of the gas molecules. They move in straight lines until they collide with another molecule. Therefore, the term for the second blank is "straight."

**Hint**: Consider the path taken by a moving object in the absence of external forces.

3. **Nature of collisions**: The third blank concerns the type of collisions that occur between gas molecules. These collisions are perfectly elastic, meaning that there is no loss of kinetic energy during the collision. Thus, the term for the third blank is "elastic."

**Hint**: Recall the definition of elastic collisions in physics.

4. **Conditions for ideal gas behavior**: The fourth and fifth blanks relate to the conditions under which a real gas behaves like an ideal gas. A real gas behaves as an ideal gas at high temperature, where the kinetic energy of the molecules is high enough to overcome intermolecular forces, and at low pressure, where the volume of the gas particles is negligible compared to the volume of the container. Therefore, the terms for the fourth and fifth blanks are "high" and "low," respectively.

**Hint**: Think about the effects of temperature and pressure on gas behavior; high temperature and low pressure are key conditions.

Putting it all together, the completed sentence is:
The molecules of a gas are in constant (i) **random** motion. They move in (ii) **straight** lines until they collide with another molecule. The collisions are perfectly (iii) **elastic** in nature. A real gas behaves as an ideal gas at (iv) **high** temperature and (v) **low** pressure.

**Final Answer**:
(i) random
(ii) straight
(iii) elastic
(iv) high
(v) low