A long iron rod is partially dipped in common salt solution. What happens?

Explanation

### Step-by-Step Solution:

1. **Understanding the Setup**: We have a long iron rod that is partially dipped in a common salt solution, which is primarily sodium chloride (NaCl) dissolved in water.

2. **Referencing the Activity Series**: To predict what happens when the iron rod is dipped in this solution, we need to refer to the metal activity series. This series ranks metals based on their ability to displace other metals from compounds.

3. **Identifying the Metals**: In this case, we have sodium (Na) from the salt (NaCl) and iron (Fe) from the iron rod. According to the activity series, sodium is placed above iron.

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