How many varieties of heavy water are possible in terms of 3 different isotopes of oxygen

Explanation

To determine how many varieties of heavy water can be formed using the three different isotopes of oxygen (O-16, O-17, and O-18) along with deuterium (D) and protium (H), we can follow these steps:

### Step 1: Understand the Composition of Heavy Water
Heavy water is primarily composed of deuterium (D) instead of the regular hydrogen (H). The two main forms of heavy water are:
1. D2O (where both hydrogen atoms are deuterium)
2. HDO (where one hydrogen atom is deuterium and the other is protium)

### Step 2: Identify the Isotopes of Oxygen
We have three isotopes of oxygen to consider:
1. O-16
2. O-17
3. O-18

### Step 3: Combine Isotopes of Oxygen with Heavy Water Forms
Now, we can combine these isotopes with the two forms of heavy water:

1. **For D2O**:
- D2O with O-16 → D2O-16
- D2O with O-17 → D2O-17
- D2O with O-18 → D2O-18

This gives us **3 varieties** of D2O.

2. **For HDO**:
- HDO with O-16 → HDO-16
- HDO with O-17 → HDO-17
- HDO with O-18 → HDO-18

This gives us **3 varieties** of HDO.

### Step 4: Calculate Total Varieties of Heavy Water
Now, we can add the varieties from both forms:
- Varieties from D2O: 3
- Varieties from HDO: 3

Total varieties of heavy water = 3 (from D2O) + 3 (from HDO) = **6 varieties**.

### Final Answer
Thus, the total number of varieties of heavy water possible with the three different isotopes of oxygen is **6**.

---