Isotopes have

Options

A. same number of protons
B. Same number of neutrons
C. Different number of electrons
D. Different atomic numbers

Answer

### Step-by-Step Solution:

1. **Understanding Isotopes**:
- Isotopes are defined as atoms of the same element that have the same number of protons but different numbers of neutrons. This results in different atomic masses for these isotopes.

2. **Identifying Key Characteristics**:
- Since isotopes have the same number of protons, they belong to the same element and thus have the same atomic number.
- The difference in the number of neutrons leads to a difference in atomic mass.

3. **Analyzing the Statements**:
- **Statement 1**: "Same number of protons" - This is correct because isotopes have the same atomic number.
- **Statement 2**: "Same number of neutrons" - This is incorrect because isotopes differ in the number of neutrons.
- **Statement 3**: "Different number of electrons" - This is also incorrect because in neutral atoms, the number of electrons equals the number of protons.
- **Statement 4**: "Different atomic number" - This is incorrect as isotopes have the same atomic number.

4. **Conclusion**:
- The only correct statement regarding isotopes is that they have the same number of protons.

### Final Answer:
- Isotopes have the same number of protons (same atomic number) but differ in the number of neutrons and atomic mass.