The element that has 11 protons in its nucleus is Sodium.
Here's a brief explanation to understand why:
1. Sodium is a chemical element with the symbol Na and atomic number 11.
2. The atomic number of an element corresponds to the number of protons in its nucleus.
3. Since Sodium has an atomic number of 11, it means it has exactly 11 protons in its nucleus.
4. Therefore, among the options provided (Sodium, Magnesium, and Calcium), Sodium is the element with 11 protons.
