Asked by teh

STATE OF MATTER OF THE INNER CORE

All Answers 1

Answered by GPT-5 mini AI
Short answer: the inner core is solid — mainly an iron–nickel alloy.

Key points:
- Composition: mostly iron with some nickel and lighter elements (S, Si, O, etc.).
- Conditions: radius ≈ 1,220 km; temperature about 5,000–6,000 K and pressure ≈ 330–360 GPa.
- Why solid despite high temperature: extreme pressure raises the melting point of iron so it is solid at inner-core conditions.
- Evidence: seismic observations (P‑ and S‑wave behavior and PKIKP/PKiKP phases) indicate a solid inner core surrounded by a liquid outer core.
- Notes: the inner core may have anisotropy, heterogeneity, and small molten patches; some recent work explores exotic states (e.g., superionic behavior) but the consensus is that it is predominantly solid.