# Explain why lithium fluoride (LiF) is described as an ionic compound and outline the process by which it forms from its constituent elements.

> IB DP Chemistry Standard Level (2023 syllabus) — S2.1 The ionic model · Explain · 4 marks

## Mark scheme (4 marks)

1. LiF consists of oppositely charged ions (Li⁺ and F⁻) held together by electrostatic attraction
2. Lithium (a metal) transfers/loses one electron to fluorine (a non-metal)
3. Lithium achieves the electron configuration of helium (1s²) / a full outer shell, forming Li⁺
4. Fluorine achieves the electron configuration of neon (2,8) / a full outer shell, forming F⁻

## Related

- [Revision notes for IB DP Chemistry Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-lithium-fluoride-lif-is-60f87b94) · Published by Druglandscape Ltd.