The correct electron dot structure of a water molecule is

Options

A.
B.
C.
D.

Explanation

To determine the correct electron dot structure of a water molecule (H₂O), we can follow these steps:

### Step 1: Identify the central atom
The water molecule consists of two hydrogen atoms and one oxygen atom. Oxygen (O) will be the central atom because it is more electronegative than hydrogen.

### Step 2: Determine the number of valence electrons
Oxygen has 6 electrons in its valence shell (as per its electronic configuration: 2, 6). Each hydrogen atom has 1 electron in its valence shell. Therefore, the total number of valence electrons in H₂O is:
- Oxygen: 6 electrons
- Hydrogen: 1 electron × 2 = 2 electrons
- Total = 6 + 2 = 8 valence electrons

### Step 3: Draw the electron dot structure for oxygen
We start by drawing the 6 valence electrons around the oxygen atom. This can be represented as:
- 1 dot for each of the 6 electrons:
```
•
• • • •
•
```

### Step 4: Add hydrogen atoms
Each hydrogen atom will share its single electron with oxygen. We can represent the hydrogen electrons as crosses (×). When we add the hydrogen atoms, we will show the sharing of electrons:
- For the first hydrogen:
```
•
• • • •
• ×
```
- For the second hydrogen:
```
•
• • • •
• × ×
```

### Step 5: Show the shared electrons
Now, we need to indicate that the hydrogen atoms are sharing their electrons with oxygen. After sharing, the structure will look like this:
```
•
• • • •
• ×
• ×
```
This indicates that oxygen has 2 electrons shared with hydrogen and still has 4 unshared electrons.

### Step 6: Finalize the structure
The final electron dot structure of the water molecule shows that oxygen has 4 unshared electrons and is bonded to two hydrogen atoms. The correct representation will show:
- 6 electrons around oxygen (2 shared with hydrogen, 4 unshared).

### Conclusion
The correct electron dot structure of a water molecule (H₂O) is represented as follows, where the dots represent the electrons and the crosses represent the shared electrons from hydrogen:
```
•
• • • •
• ×
• ×
```
Thus, the correct answer is option number 3, which indicates the arrangement of electrons in the water molecule.

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