Respuesta :
As you can see in the picture presented below, Helium (He) is a noble gas with a stable 1s2 electron configuration.
This means that an atom of Helium has two electrons that are orbiting the atom's core in the first, S orbit. The two electrons are in the same orbit, but they orbit in opposite directions, they have an opposite spin.
This means that an atom of Helium has two electrons that are orbiting the atom's core in the first, S orbit. The two electrons are in the same orbit, but they orbit in opposite directions, they have an opposite spin.
Answer is in the picture below.
Helium (symbol: He) is an element with atomic number 2 (two protons and two electrons) and mass number 4 (2 neutrons; n° = 4 - 2 = 2).
Electron configuration of helium atom: ₂He 1s².
Helium is a noble gas.
Noble gases are in group 18: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn). They have very low chemical reactivity.