Question

Ionic or molecular
CsF?
KCN?
HF?

Answer 1

To determine whether the compounds CsF, KCN, and HF are ionic or molecular, we can look at their constituent elements and the nature of their bonding.

1. **CsF (Cesium fluoride)**:
- **Type**: Ionic
- **Reason**: Cs (cesium) is a metal and F (fluorine) is a non-metal. The difference in electronegativity between cesium and fluorine is significant, leading to the transfer of electrons from cesium to fluorine, resulting in the formation of positive and negative ions (Cs⁺ and F⁻).

2. **KCN (Potassium cyanide)**:
- **Type**: Ionic
- **Reason**: K (potassium) is a metal, and CN (cyanide) acts as a polyatomic ion (C≡N⁻). The bond between K and the CN⁻ ion involves the transfer of an electron, characteristic of ionic compounds.

3. **HF (Hydrogen fluoride)**:
- **Type**: Molecular
- **Reason**: HF consists of two non-metals (H and F). The bonding in HF involves the sharing of electrons rather than the transfer of electrons, which is characteristic of molecular compounds. This leads to a polar covalent bond due to the difference in electronegativity between hydrogen and fluorine.

In summary:
- CsF: Ionic
- KCN: Ionic
- HF: Molecular