Which of the following elements are isotopes

Options

A. `C^(12)`
B. `C^(13)`
C. `C^(14)`
D. `N^(14)`

Explanation

To determine which of the given elements are isotopes, we need to follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Isotopes**:
- Isotopes are atoms of the same element that have the same atomic number but different mass numbers. This means they have the same number of protons but a different number of neutrons.

2. **Identify the Elements Given**:
- We are provided with four different elements. Let's denote them as Element A, Element B, Element C, and Element D.

3. **Determine the Atomic Numbers**:
- Look up the atomic numbers of the elements. For example, if we have three carbon atoms (C) and one nitrogen atom (N):
- Carbon (C) has an atomic number of 6.
- Nitrogen (N) has an atomic number of 7.

4. **Check for Same Atomic Number**:
- From the elements, identify which ones have the same atomic number. In our example, all three carbon atoms have the atomic number 6, while the nitrogen atom has an atomic number of 7.

5. **Check for Different Mass Numbers**:
- Next, we need to check the mass numbers of the isotopes. For carbon, the isotopes can be Carbon-12, Carbon-13, and Carbon-14. These have the same atomic number (6) but different mass numbers (12, 13, and 14).

6. **Conclusion**:
- Since the carbon atoms have the same atomic number and different mass numbers, they are isotopes. The nitrogen atom does not qualify because it has a different atomic number.

7. **Final Answer**:
- The elements that are isotopes are the three forms of carbon (C-12, C-13, and C-14).

### Summary of the Answer:
- The isotopes among the given elements are the three carbon isotopes (C-12, C-13, and C-14).