Calculate the oxidation state of the underlined atoms in the given species.
(d) `ulCr_(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 1: Identify the known oxidation states
In the dichromate ion, we know that oxygen (O) typically has an oxidation state of \(-2\).

### Step 2: Set up the equation
Let the oxidation state of chromium (Cr) be \(X\). Since there are 2 chromium atoms in the dichromate ion, we can express the total contribution of chromium to the oxidation state as \(2X\). The contribution from the 7 oxygen atoms is \(7 \times (-2) = -14\).

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