This is the timeline of events for the Periodic Table Universe. The time scale used is BPTE and PTE which stand for Before Periodic Table Era and Periodic Table Era respectively.
- 13,000,000,000 BPTE – The universe is formed
- 1,933,000 BPTE – Earliest known record of the Dark Matter Empire.
- Emperor Axion is crowned as the first ruler of the Dark Matter Empire.
- 100,000 BPTE – The Dark Matter Empire mysteriously vanishes.
- 0 PTE – The government for the galaxy is formed as the Periodic Table.
- 879 PTE – A volcanic eruption destroys an ancient city on Eich-Tuo leaving behind the Lava Temple.
- 956 PTE – A war takes place on Planet Eich-Tuo. This leaves behind a location known as the Haunted Bastion.
- 1893 PTE – The events of Elementals take place.
- Lord Radon secedes temporarily from the Noble Gas Provinces and recruits Iron and Nitrogen to conduct a coup.
- The Plutonium Overlord is defeated and a peace treaty is formed over the warring noble gas houses.
- This is the first year of the annual Galactic Science Expo.
- 1937 PTE – Dr. Ruby Dium is born.
- 1939 PTE – Professor Humphry is born.
- 1952 PTE – The events of Droplet and the Prototype Machine take place.
- The Weather Machine Mark I is created.
- Fireling attacks planet Eich-Tuo.
- Humphry defeats Fireling.
- 1956 PTE – The events of Droplet 2: Fusion Power take place.
- The Weather Machine Mark II is created.
- Fireling returns once more to attack planet Eich-Tuo.
- Humphry defeats Fireling again.
- 1982 PTE – Molly “Molly-QL” Watari is born.
- 1985 PTE – Drew “Droplet” Watari is born.
- 1998 PTE – The Watari Siblings begin their career as musicians under the name “Droplet and Molly-QL”.
- 1999 PTE – The events of Droplet: States of Matter take place.
- Galactic Science Expo 1999 takes place.
- Professor Humphry demonstrates the Weather Machine Mark III.
- Lord Krypton attempts to monopolize crystal power. With the collaboration of Dr. Ruby Dium, all of the crystals are stolen and sent into the black market.
- Droplet and Molly-QL venture across the Noble Gas Provinces to recover all the lost crystals.
Droplet • Molly-QL • Professor Humphry Heisenberg Otto • Dr. Ruby Dium • Lord Krypton • Professor Stratus • Fireling • Princess Cara Bonnie • Kalofrioh • Sobek • Captain Salty Peter • Sill E. Con • Tachyon Gang • Iron • Nitrogen • Lord Radon • Plutonium Overlord • King Kelvin • Emperor Axion
Tree Frogs • Fire Grunts • Gorgon • Coriphant • Mad Hatter
Galactic Science Expo • Orgel’s • Fossil Corp