Calculate the oxidation state of the underlined atoms in the given species.
(d) `ul©r_(2)O_(7)^(2-)`

Explanation

To calculate the oxidation state of chromium (Cr) in the dichromate ion \( \text{Cr}_2\text{O}_7^{2-} \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Species**: We are given the dichromate ion, which is represented as \( \text{Cr}_2\text{O}_7^{2-} \).

2. **Assign Oxidation States**:
- Let the oxidation state of chromium (Cr) be \( x \).
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