Periodic table, John R. P.1

Edit Answers
123456
Across
  1. 2. I have no valor electrons, more than 4.5 times the weight of air. I'm colorless, odorless, and tasteless.
  2. 5. I have 57 neutrons
  3. 6. I have valor electrons and am a superconductor at my freezing temperature
Down
  1. 1. I am synthetic, and have less than 84 neutrons
  2. 3. I'm named after a country with a Deutsche name of Franchriech
  3. 4. I have 2 valor electrons and more than 121 neutrons but less than 173