A helium atom has two electrons in an energy level outside the nucleus. The atom is neutral as it has two positive protons and two negative electrons. A helium atom that has lost or gained an ...

Long before stars lit up the sky, the universe was a hot, dense place where simple chemistry quietly set the stage for ...

A team of physicists Led by Florian Grussie of the Max Planck Institute for Nuclear Physics (MPIK) in Germany has reproduced ...

Mainz, 2021: a team of researchers bombarded helium-4 nuclei with electrons, aiming to observe the transition of this nucleus, also known as the alpha particle, from its ground state to its first ...

Crystal structure of Na₂He, which resembles a 3D checkerboard. The purple spheres represent sodium atoms, which are inside the green cubes that represent helium atoms.

Most Precise Measurement Ever Made Of Helium-6 Charge Radius Date: November 5, 2004 Source: Argonne National Laboratory Summary: Researchers in Argonne's Physics Division teamed up to conduct the ...

J. C. Slater, The Structure of the Helium Atom. I, Proceedings of the National Academy of Sciences of the United States of America, Vol. 13, No. 6 (Jun. 15, 1927), pp. 423-430 ...