The radioactive isotope of hydrogen is called ……….. And its nucleus contains ……….. Proton and ……….. Neutrons.

Answer

To answer the question, we need to identify the radioactive isotope of hydrogen and the composition of its nucleus in terms of protons and neutrons.

### Step-by-Step Solution:

1. **Identify the Isotopes of Hydrogen**:
- Hydrogen has three isotopes:
- Protium (¹H) - the most common isotope with no neutrons.
- Deuterium (²H) - has one neutron.
- Tritium (³H) - the radioactive isotope of hydrogen.

2. **Determine the Name of the Radioactive Isotope**:
- The radioactive isotope of hydrogen is called **Tritium**.

3. **Identify the Number of Protons**:
- All isotopes of hydrogen have the same number of protons, which is **1** (since hydrogen has an atomic number of 1).

4. **Identify the Number of Neutrons**:
- Tritium has two neutrons in its nucleus. This can be determined by subtracting the number of protons from the mass number of tritium (which is 3).
- Therefore, Tritium has **2 neutrons**.

### Final Answer:
The radioactive isotope of hydrogen is called **Tritium** and its nucleus contains **1 proton** and **2 neutrons**.

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