Highest group valency of halogens with respect to oxygen is___________.

Explanation

To determine the highest group valency of halogens with respect to oxygen, we can follow these steps:

### Step 1: Understand the Concept of Valency
Valency refers to the combining capacity of an element, which can be defined as the number of electrons an atom can lose, gain, or share during a chemical reaction.

**Hint:** Valency is related to the number of electrons in the outermost shell of an atom.

### Step 2: Identify the Group of Halogens
Halogens belong to Group 17 of the periodic table. Their general electronic configuration is \( ns^2 np^5 \).

**Hint:** Remember that halogens are located in Group 17, which influences their chemical behavior.

### Step 3: Determine the Oxidation States of Halogens
Halogens can exhibit multiple oxidation states. The highest oxidation state of halogens with respect to oxygen is +7. This occurs because halogens can form compounds where they are bonded to oxygen, leading to a higher oxidation state.

**Hint:** Oxidation states indicate how many electrons an atom has gained or lost compared to its elemental state.

### Step 4: Provide Examples
Examples of halogens in the +7 oxidation state include compounds like \( ClO_4^- \) (perchlorate) and \( BrO_4^- \) (perbromate).

**Hint:** Look for common compounds that illustrate the highest oxidation states of halogens.

### Step 5: Conclusion
Thus, the highest group valency of halogens with respect to oxygen is +7.

**Final Answer:** The highest group valency of halogens with respect to oxygen is +7.