The question is based on a common misconception. The Earth's layer is known as "NIFE," not "knife".
Here's a breakdown:
The innermost layer of the Earth, known as the core, is primarily composed of nickel and iron. Therefore, it is sometimes referred to as NIFE, combining the chemical symbols for nickel (Ni) and iron (Fe). This term “NIFE” is a shorthand to represent this specific metal composition of the Earth's core.
Here's a table summarizing the Earth's layers and what they are known for:
| Layer | Composition | Nickname |
|---|---|---|
| Crust | Solid rock (basalt, granite) | Lithosphere |
| Mantle | Hot, dense silicate rocks | |
| Outer Core | Liquid iron and nickel | |
| Inner Core | Solid iron and nickel | NIFE |
Therefore, while the question uses "knife", it seems it intended to ask about the "NIFE" layer, which is the core because it's primarily composed of nickel and iron.
