Dihydrogen has :

Options

A. two isotopes and no isomers.
B. three isotopes and two spin isomers.
C. three isotopes and two geometrical isomers.
D. two isotopes and two optical isomers

Explanation

To solve the question regarding the properties of dihydrogen (H₂), we will analyze the options given and determine the correct characteristics of dihydrogen.

### Step-by-Step Solution:

1. **Understanding Dihydrogen**:
- Dihydrogen refers to the molecular form of hydrogen, which is H₂.

2. **Identifying Isotopes**:
- Isotopes are atoms of the same element that have the same atomic number but different mass numbers.
- For hydrogen, the isotopes are:
- Protium (¹H) with a mass number of 1.
- Deuterium (²H) with a mass number of 2.
- Tritium (³H) with a mass number of 3.
- Therefore, hydrogen has **three isotopes**: Protium, Deuterium, and Tritium.

3. **Identifying Spin Isomers**:
- Spin isomers are forms of a molecule that have the same mass number and atomic composition but differ in the arrangement of their nuclear spins.
- Dihydrogen has two spin isomers:
- Ortho-hydrogen: where the spins of the two protons are aligned parallel.
- Para-hydrogen: where the spins of the two protons are aligned antiparallel.
- Thus, dihydrogen has **two spin isomers**.

4. **Conclusion**:
- Combining the information from the previous steps, we conclude that dihydrogen has **three isotopes** (Protium, Deuterium, Tritium) and **two spin isomers** (Ortho-hydrogen and Para-hydrogen).

### Final Answer:
Dihydrogen has three isotopes and two spin isomers.

---