# What is the (kinetic) energy range of a particle in Bose condensate?

Bose–Einstein condensate (BEC) is a state of matter that is typically formed when a gas of bosons at low densities is cooled to temperatures very close to absolute zero (−273.15 °C or −459.67 °F).

The kinetic energy of a Bose condensate is on the order of one nanokelvin.

This is confusing to me, as i though kelvin was units for temperature only.

What is (kinetic) energy range of a typical particle in Bose condensate.

• You can convert temperature (Kelvin) to energy by multiplying the Boltzmann constant $k_B$ Commented Jan 30, 2022 at 13:53

Leaving aside that, as the comment points out, energy and temperature are related by: $$E = k_B T$$, where $$k_B$$ is the Boltzmann constant.
Kinetic energy usually refers to the "quantum kinetic energy" or quantum pressure: $$E_k = \int \mathrm{d}\mathbf{r}\, \frac{\hbar^2}{2m} |\nabla \sqrt{n}|^2,$$ which quantifies the energy stored in the gas because of its spatial distribution. In a free gas, the cloud would be uniform density, no curvature, hence zero "kinetic" energy.