What is Heliums electron configuration?

Answer 1

As it has two postively charged protons in it (along with two neutrons), a Helium nucleus has two electrons 'orbiting' around it. Knowing this, we need to find which orbits they are in.

The lowest energy orbital in an atom is made up of a single 'S' orbital (the 's' describes its shape - spherical) with a principal quantum number of 1 (which indicates the size of the orbital, 1 being the smallest). This is therefore denoted 1s . This orbital can accept two electrons, so both of the helium electrons go into it. The way to express this as a electron configuration is 1s2 , the superscript '2' indicating the number of electrons in the orbital.

Feel free to stop at that point. To be a bit more technical, when we write 1s2 the '1s' is actually a mathematical wavefunction, and the superscript '2' is there because there are two electrons whose wavefunction is 1s, and so we multiply those wavefunctions together - hence the configuration actually means 1s-squared.

Answer 2

The electron configuration of helium is 1s2.

Answer 3

The electron configuration of helium is 1s^2, indicating that it has two electrons in its 1s orbital.