How many protons does an atom with an atomic number of 23 and a mass number of 51 have?

Options

A. 23
B. 28
C. 51
D. 74

Explanation

To determine how many protons an atom has, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- The **atomic number** of an atom is defined as the number of protons present in the nucleus of that atom.
- The **mass number** is the total number of protons and neutrons in the nucleus.

2. **Identify the Given Information**:
- The question provides an atomic number of **23** and a mass number of **51**.

3. **Relate Atomic Number to Protons**:
- Since the atomic number is equal to the number of protons, we can directly state that the number of protons in this atom is equal to the atomic number.

4. **Conclusion**:
- Therefore, the number of protons in the atom is **23**.

### Final Answer:
The atom with an atomic number of 23 has **23 protons**.

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