What ions, must be present in a solution used for electroplating a particular metal?

Explanation

To answer the question about what ions must be present in a solution used for electroplating a particular metal, we can follow these steps:

### Step-by-Step Solution

1. **Understanding Electroplating**: Electroplating is a process where a layer of metal is deposited onto a surface using electric current. The metal to be deposited must be available in ionic form in the solution.

2. **Identifying the Metal to be Electroplated**: Determine the specific metal you want to electroplate onto another object. For example, if you want to electroplate gold, then you need gold ions in the solution.

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