Salt concentration (salinity) of the sea measured in parts per thousand is

Options

A. 10-15
B. 30-70
C. 0 - 5
D. 30 - 35

Answer

To solve the question regarding the salt concentration (salinity) of the sea measured in parts per thousand, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Salinity**:
- Salinity refers to the concentration of salts in water, often expressed in parts per thousand (ppt). This is a common measurement used in oceanography to describe the saltiness of seawater.

2. **Identifying the Range of Salinity in Different Water Bodies**:
- The salinity of different water bodies varies significantly:
- **Sea/Ocean**: Typically has a salinity range.
- **Inland Waters**: Generally have a much lower salinity.
- **Lagoons**: Can have very high salinity levels.

3. **Determining the Salinity of the Sea**:
- The salinity of the sea is generally accepted to be between **30 to 35 parts per thousand** (ppt). This is a well-established fact in marine biology and oceanography.

4. **Evaluating the Options**:
- Given the options:
- A) 10 to 15
- B) 30 to 70
- C) 0 to 5
- D) 30 to 35
- We can see that option D (30 to 35) matches the known salinity range for seawater.

5. **Conclusion**:
- Therefore, the correct answer to the question about the salt concentration (salinity) of the sea is **option D: 30 to 35 parts per thousand**.