Which of the following inert gas liquifies easily

Options

A. Kr
B. He
C. Ne
D. Ar

Explanation

To determine which inert gas liquefies easily, we can follow these steps:

### Step 1: Identify the Inert Gases
The inert gases, also known as noble gases, include:
- Helium (He)
- Neon (Ne)
- Argon (Ar)
- Krypton (Kr)
- Xenon (Xe)

### Step 2: Understand the Trend in Boiling Points
As we move down the group in the periodic table from helium to xenon, the atomic size increases. This increase in size leads to an increase in the boiling points of these gases.

### Step 3: Analyze the Boiling Points
The boiling points of the noble gases are as follows:
- Helium: -269 °C
- Neon: -246 °C
- Argon: -186 °C
- Krypton: -157 °C
- Xenon: -108 °C

From this data, we can see that as we go from helium to xenon, the boiling point increases.

### Step 4: Determine Which Gas Liquefies Easily
Since the boiling point is a measure of how easily a gas can be liquefied, the gas with the highest boiling point will liquefy more easily. Among the noble gases listed, xenon has the highest boiling point, followed by krypton.

### Step 5: Conclusion
Therefore, the inert gas that liquefies easily is **Xenon (Xe)**, followed closely by **Krypton (Kr)**.

### Final Answer
**Xenon (Xe) liquefies easily among the inert gases.**