The density of elemental sodium at room temperature (about 20 °C) is roughly 0.97 g/cm³ , which is the same as about 970–971 kg/m³.

Basic facts

  • Sodium is a soft, reactive alkali metal with atomic number 11 and a solid density around 0.97 g/cm³ at room temperature.
  • This means sodium is less dense than water (about 1.0 g/cm³), so a piece of solid sodium would float before reacting.

Density at different conditions

  • As a solid near room temperature: about 0.97 g/cm³ (≈971 kg/m³).
  • As a solid closer to melting point: commonly reported around 0.95–0.97 g/cm³, depending on the exact temperature and source.
  • As a liquid at its melting point, the density drops slightly to about 0.93 g/cm³ and continues to decrease with higher temperature (for example ~0.86 g/cm³ at 400 °C).

Quick comparison

  • Water at room temperature: ~1.0 g/cm³ (1000 kg/m³).
  • Sodium at room temperature: ~0.97 g/cm³ (971 kg/m³), so it is slightly less dense than water.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.