Here are 11 gases that occur naturally in the Earth's atmosphere:

1. Nitrogen (N₂): The most abundant gas, making up about 78% of the atmosphere.

2. Oxygen (O₂): Essential for respiration and making up about 21% of the atmosphere.

3. Argon (Ar): An inert gas, making up about 0.93% of the atmosphere.

4. Carbon Dioxide (CO₂): A greenhouse gas, essential for plant life and making up about 0.04% of the atmosphere.

5. Neon (Ne): An inert gas, found in small amounts in the atmosphere.

6. Helium (He): An inert gas, found in trace amounts in the atmosphere.

7. Krypton (Kr): An inert gas, found in very small amounts in the atmosphere.

8. Xenon (Xe): An inert gas, found in extremely small amounts in the atmosphere.

9. Hydrogen (H₂): A highly reactive gas, found in very small amounts in the atmosphere.

10. Methane (CH₄): A potent greenhouse gas, found in trace amounts in the atmosphere.

11. Ozone (O₃): A gas found in the stratosphere that protects us from harmful UV radiation.

Note: The concentrations of these gases can vary depending on location and time.