Which of the following statements is right?

Options

A. Sodium has the atomic number of 11
B. Sodium has the atomic number of 23
C. Calcium has the atomic number of 21
D. Lithium has the atomic number of 12

Answer

To determine which of the statements is correct, we need to verify the atomic numbers of the elements mentioned in each statement.

### Step-by-Step Solution:

1. **Check the atomic number of Sodium (Na)**:
- Sodium is a chemical element with the symbol Na.
- The atomic number of Sodium is **11**.

2. **Check the atomic number of Sodium again**:
- One of the statements claims that Sodium has an atomic number of **23**.
- This is incorrect; Sodium's atomic number is **11**.

3. **Check the atomic number of Calcium (Ca)**:
- Calcium is a chemical element with the symbol Ca.
- The atomic number of Calcium is **20**.
- This statement is correct.

4. **Check the atomic number of Lithium (Li)**:
- Lithium is a chemical element with the symbol Li.
- The atomic number of Lithium is **3**, not **30**.
- This statement is incorrect.

5. **Check the atomic number of Sodium again**:
- The statement claims that Sodium has an atomic number of **30**.
- This is also incorrect; Sodium's atomic number is **11**.

### Conclusion:
The only correct statement among the options provided is that **Calcium has the atomic number of 20**.

### Final Answer:
The correct statement is: **Calcium has the atomic number of 20.**