Which of the following represent correct values for the normal atmospheric pressure ?
A.101.3 kilopascals B.76 mm of mercury C.101.3 pascals D.76 cm of mercury.

Options

A. A and B
B. B and C
C. A and D
D. B and D

Answer

To determine which of the options represent the correct values for normal atmospheric pressure, we need to understand the standard value of atmospheric pressure at sea level.

### Step-by-Step Solution:

1. **Know the Standard Value of Atmospheric Pressure**:
- The normal atmospheric pressure at sea level is approximately 101.3 kilopascals (kPa) or 760 millimeters of mercury (mmHg).

2. **Evaluate Each Option**:
- **Option A: 101.3 kilopascals (kPa)**:
- This is correct because it matches the standard value of atmospheric pressure.

- **Option B: 76 mm of mercury (mmHg)**:
- This is incorrect. The standard value is 760 mmHg, not 76 mmHg.

- **Option C: 101.3 pascals (Pa)**:
- This is incorrect. 101.3 kPa is equal to 101300 Pa, which is much larger than 101.3 Pa.

- **Option D: 76 cm of mercury (cmHg)**:
- This is correct. Since 1 cm = 10 mm, 76 cm is equal to 760 mmHg, which matches the standard atmospheric pressure.

3. **Conclusion**:
- The correct values for normal atmospheric pressure from the options provided are:
- **Option A: 101.3 kPa**
- **Option D: 76 cm of mercury**

### Final Answer:
The correct options are A (101.3 kPa) and D (76 cm of mercury).

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