Two nuclei are not identical but have the same number of nucleons. These are

Options

A. Isotopes
B. Isobars
C. Isotones
D. None

Answer

To solve the question, we need to identify the term that describes two nuclei that are not identical but have the same number of nucleons. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the terms involved
- **Nucleons**: These are the particles found in the nucleus of an atom, which include protons and neutrons. The total number of nucleons in a nucleus is referred to as the mass number (A).
- **Atomic Number (Z)**: This is the number of protons in the nucleus of an atom, which determines the element.

### Step 2: Define the relationship between nucleons and atomic number
- Two nuclei can have the same mass number (same total number of nucleons) but different atomic numbers. This means they have different numbers of protons and, consequently, they are different elements.

### Step 3: Identify the specific term for such nuclei
- Nuclei that have the same mass number but different atomic numbers are known as **isobars**.

### Step 4: Conclusion
- Therefore, the answer to the question is that the two nuclei that are not identical but have the same number of nucleons are called **isobars**.

### Final Answer:
The two nuclei that are not identical but have the same number of nucleons are called **isobars**.

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