helion

The story

1. Proto-Indo-European*sóh₂wl̥
2. Proto-Indo-European*sh₂wél(i)yos
3. Proto-Hellenic*hāwélios
4. Ancient Greekἥλιος (hḗlios)
5. New Latinhelium
6. Englishhelium
7. Ancient Greekἤλεκτρον (ḗlektron)
8. Latinēlectrum
9. New Latinēlectricus
10. Englishelectric
11. Proto-Indo-European*h₁ey-
12. Proto-Indo-European*h₁éyti
13. Proto-Hellenic*éimi
14. Ancient Greekἰόν (ión)
15. Englishion
16. Englishelectronbf.
17. English todayhelion

From helium + -on.