potassium density
Potassium metal is very low‑density: about 0.86–0.86 g/cm³ at room temperature, meaning it is less dense than water and will float.
Key numbers
- Density of solid potassium (20 °C): about 0.856–0.862 g/cm³ (≈856–862 kg/m³).
- This is why potassium can float on water, even though it reacts violently with it.
Context and comparisons
- Potassium is one of the least dense metals; its density is:
- Lower than water (≈1.0 g/cm³).
* Much lower than common structural metals like iron (≈7.9 g/cm³) or aluminum (≈2.7 g/cm³).
- As temperature approaches its melting point (about 63 °C), the density decreases slightly further in the liquid state.
Quick reference table
| Substance | Approx. density at room temp |
|---|---|
| Potassium (solid) | 0.86 g/cm³ ≈ 860 kg/m³ |
| Water | 1.0 g/cm³ ≈ 1000 kg/m³ |
| Aluminum | 2.7 g/cm³ |
| Iron | 7.9 g/cm³ |