Nobel gases do not occur in _______

Options

A. Sea water
B. atmosphere
C. Ores
D. Natural gas

Answer

To solve the question "Noble gases do not occur in _______", we need to analyze the options provided and understand where noble gases are typically found.

### Step-by-Step Solution:

1. **Understanding Noble Gases**: Noble gases are a group of elements in Group 18 of the periodic table, which include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). They are known for their lack of reactivity due to having a full valence shell of electrons.

2. **Analyzing the Options**:
- **Seawater**: Noble gases are not typically found dissolved in seawater. While some trace amounts may be present, they do not occur in significant quantities.
- **Atmosphere**: Noble gases are present in the atmosphere. For example, argon makes up about 0.93% of the Earth's atmosphere.
- **Ores**: Noble gases can be found in certain ores, particularly those that contain radioactive elements, which can release radon gas.
- **Natural Gas**: Noble gases, particularly helium, can also be found in some natural gas deposits.

3. **Conclusion**: Based on the analysis, noble gases do not occur in seawater in significant amounts compared to the other options provided.

### Final Answer:
Noble gases do not occur in **seawater**.

---