Explain why :
A blue or green colour in the flame is obtained during Beilstein's test for halogens.

Explanation

### Step-by-Step Solution:

1. **Understanding Beilstein's Test**:
Beilstein's test is a qualitative analysis method used to detect the presence of halogens (such as chlorine, bromine, and iodine) in organic compounds.

2. **Procedure of Beilstein's Test**:
In this test, a clean copper wire is flattened at one end and heated in an oxidizing flame. Initially, when the copper wire is heated alone, it does not impart any color to the flame.

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