Shown following are the names of several eras that are used to descried the history of the universe. Rank the eras from left to right in the order in which they occurred from first to last.
1. era of nucleosynthesis - fusion created helium nuclei
2. particle era - protons, neutrons both common
3. era of nuclei - H, He nuclei and electrons existed, but no neutral atoms
4. era of atoms - neutral atoms existed, but not stars
5. era of galaxies - stars and galaxies common
6. Planck era - all 4 forces operated as one
7.electroweak era - 3 forces operated: gravity, strong, electroweak
8. GUT era - strong, electroweak forces unite as GUT force