Which one of the following is the most abundant gas in the earths' atmosphere other than nitrogen and oxygen?

Options

A. Argon
B. Carbon dioxide
C. Hydrogen
D. Methane

Answer

To determine which gas is the most abundant in the Earth's atmosphere, other than nitrogen and oxygen, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Gases Present in the Atmosphere**:
We know that the atmosphere is primarily composed of nitrogen (approximately 78%) and oxygen (approximately 21%). We need to look for other gases that are present in smaller amounts.

2. **List the Options Given**:
The options provided are:
- Argon
- Carbon Dioxide
- Hydrogen
- Methane

3. **Find the Percentage Composition of Each Gas**:
- **Argon**: Approximately 0.93%
- **Carbon Dioxide**: Approximately 0.04%
- **Hydrogen**: Approximately 0.0000055%
- **Methane**: Approximately 0.00017%

4. **Compare the Percentages**:
Now we compare the percentages of these gases:
- Argon: 0.93%
- Carbon Dioxide: 0.04%
- Hydrogen: 0.0000055%
- Methane: 0.00017%

5. **Determine the Most Abundant Gas**:
From the comparison, it is clear that Argon has the highest percentage composition among the gases listed.

6. **Conclusion**:
Therefore, the most abundant gas in the Earth's atmosphere, other than nitrogen and oxygen, is **Argon**.

### Final Answer:
**Argon**

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