Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but are different in their outermost shells. It was found that elements A and G combine to form an ionic compound which can also be extracted from sea water. Oxides of the elements A and B are basic in nature while those of E and F are acidic. The oxide of elements D is almost neutral.
Which of the following is likely to be halogen?

Options

A. D
B. G
C. H
D. A

Explanation

To solve the question, we will analyze the information given about the elements A, B, C, D, E, F, G, and H step by step.

### Step 1: Identify the Elements
The question states that elements A, B, C, D, E, F, G, and H have the same number of electronic shells but different electrons in their outermost shells. This means they belong to the same period in the periodic table.

### Step 2: Analyze the Ionic Compound
It is mentioned that elements A and G combine to form an ionic compound that can be extracted from seawater. The most common ionic compound extracted from seawater is sodium chloride (NaCl). Thus, we can conclude:
- A = Sodium (Na)
- G = Chlorine (Cl)

### Step 3: Determine the Nature of Oxides
Next, we analyze the nature of the oxides of the elements:
- The oxides of elements A (Na) and B are basic.
- The oxides of elements E and F are acidic.
- The oxide of element D is neutral.

### Step 4: Identify Basic Oxides
Since A = Na, we know that:
- The oxide of A (Na) is Na2O, which is basic.
- For B, since it also has a basic oxide, we can assume B is likely to be another metal. In the same period as Na, the next metal is Magnesium (Mg), so:
- B = Magnesium (Mg)
- Oxide of B = MgO, which is also basic.

### Step 5: Identify Acidic Oxides
For elements E and F, which have acidic oxides:
- E could be Phosphorus (P) with oxides like P2O5 (acidic).
- F could be Sulfur (S) with oxides like SO2 or SO3 (acidic).

### Step 6: Identify Neutral Oxide
The oxide of element D is neutral. The element that fits this description in the same period is Silicon (Si), with its oxide being SiO2, which is neutral.

### Step 7: Determine Halogen
Now, we need to identify which of the elements is likely to be a halogen. Given that G is Chlorine (Cl), it is indeed a halogen.

### Conclusion
Based on the analysis, the element that is likely to be a halogen is:
- **G = Chlorine (Cl)**