What is the valency of halogens?

Options

A. 7
B. 3
C. 1
D. 4

Explanation

To determine the valency of halogens, we can follow these steps:

### Step 1: Understand Valency
Valency is defined as the number of electrons an element gains, loses, or shares in order to achieve a stable electron configuration, typically that of a noble gas (inert gas configuration).

**Hint:** Remember that valency is related to achieving a full outer shell of electrons.

### Step 2: Identify Halogens
Halogens are the elements found in Group 17 of the periodic table. The common halogens include:
- Fluorine (F)
- Chlorine (Cl)
- Bromine (Br)
- Iodine (I)
- Astatine (At)

**Hint:** Group numbers in the periodic table can help you identify the elements belonging to a specific group.

### Step 3: Determine the Electron Configuration
The electron configurations of the halogens are as follows:
- Fluorine: 2, 7
- Chlorine: 2, 8, 7
- Bromine: 2, 8, 18, 7
- Iodine: 2, 8, 18, 32, 7

From these configurations, we can see that halogens have 7 electrons in their outermost shell.

**Hint:** Focus on the outermost shell when determining the number of electrons.

### Step 4: Calculate the Valency
To achieve a stable configuration (octet), halogens need to gain 1 electron. Therefore, the valency of halogens is 1.

**Hint:** Think about how many electrons are needed to complete the outer shell.

### Conclusion
Thus, the valency of halogens is 1.

**Final Answer:** The valency of halogens is 1.

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