To determine the number of protons in manganese-55 [tex]\(({}_{25}^{55} \text{Mn})\)[/tex], we need to look at the atomic number of the element.
1. Identify the atomic number:
- The atomic number of an element is given as a subscript to the left of the chemical symbol.
- For manganese in the notation [tex]\({}_{25}^{55} \text{Mn}\)[/tex], the atomic number is represented by the number 25.
2. Recall the significance of the atomic number:
- The atomic number of an element represents the number of protons in the nucleus of an atom of that element.
- Therefore, for manganese, with an atomic number of 25, the number of protons must be 25.
Thus, the number of protons in manganese-55 is 25.
So the correct choice among the given options is:
```
25
```.
