Generally, the valency of noble gases is

Options

A. Zero
B. one
C. three
D. two

Explanation

**Step-by-Step Solution:**

1. **Understanding Noble Gases**: Noble gases are elements found in Group 18 of the periodic table. They include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).

2. **Electronic Configuration**: The general electronic configuration of noble gases is represented as ns²np⁶. This means that their outermost shell (valence shell) is completely filled with electrons.

3. **Valency Definition**: Valency refers to the ability of an atom to bond with other atoms, which is determined by the number of electrons in the outermost shell. Atoms tend to bond in order to achieve a full outer shell.

4. **Noble Gases and Bonding**: Since noble gases have a full outer shell (8 electrons for most, except helium which has 2), they do not need to gain, lose, or share electrons to achieve stability. This means they do not typically form bonds with other atoms.

5. **Conclusion on Valency**: Because noble gases do not form bonds, their valency is considered to be 0. They are often referred to as inert or non-reactive due to this property.

6. **Final Answer**: Therefore, the valency of noble gases is 0.

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