Silver jewellery items tarnish slowly in air due to their reaction with ____.

Explanation

To answer the question about why silver jewelry items tarnish slowly in air, we can break down the process into clear steps:

### Step-by-Step Solution:

1. **Understanding Tarnishing**: Tarnishing is a chemical process that causes a metal's surface to become discolored or blackened. In the case of silver, this tarnishing occurs when it reacts with certain substances in the environment.

2. **Identifying the Reactant**: When silver (Ag) is exposed to air, it does not tarnish due to oxygen alone. Instead, the tarnishing is primarily caused by the presence of hydrogen sulfide (H₂S) in the air.

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