How many stable oxidation state of chromium is `+n`. Given the value of 'n'

Answer

To determine how many stable oxidation states of chromium exist that are equal to +n, we will analyze the electronic configuration of chromium and its common oxidation states.

### Step-by-Step Solution:

1. **Identify the Electronic Configuration of Chromium:**
- The electronic configuration of chromium (Cr) is:
\[ \text{Cr: } [\text{Ar}] 4s^1 3d^5 \]
- This shows that chromium has a total of 6 valence electrons (1 from 4s and 5 from 3d).

2. **Determine Possible Oxidation States:**
- Chromium can lose electrons from both the 4s and 3d orbitals. The possible oxidation states of chromium can be:
- +1 (losing 1 electron)
- +2 (losing 2 electrons)
- +3 (losing 3 electrons)
- +4 (losing 4 electrons)
- +5 (losing 5 electrons)
- +6 (losing all 6 electrons)
- Thus, the possible oxidation states are +1, +2, +3, +4, +5, and +6.

3. **Identify the Stable Oxidation States:**
- Among these oxidation states, we need to identify which ones are stable:
- **+2 oxidation state (Cr²⁺):** This state has the electronic configuration of \(d^4\). The stability arises because it can achieve a relatively stable configuration.
- **+3 oxidation state (Cr³⁺):** This state has a \(d^3\) configuration, which is half-filled and thus particularly stable due to exchange energy.
- **+6 oxidation state (Cr⁶⁺):** This state achieves a noble gas configuration (similar to Argon) after losing all six valence electrons, making it stable.

4. **Count the Stable Oxidation States:**
- The stable oxidation states of chromium are +2, +3, and +6. Therefore, there are a total of **three stable oxidation states** for chromium.

### Final Answer:
The number of stable oxidation states of chromium is **3**.

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