Which zone of a flame does a goldsmith use for melting gold and silver and why?

Explanation

**Step-by-Step Solution:**

1. **Identify the Zone of the Flame Used by Goldsmiths:**
- Goldsmiths use the outermost part of the flame, which is known as the outer zone or outer flame zone.

2. **Explain the Purpose of Using This Zone:**
- The outer zone of the flame is utilized for melting metals like gold and silver. This is because it provides the necessary heat required for melting these metals.

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