Down there (pls hurry!!) 6

What term is missing from the central region that describes hypotheses, theories, and laws? popular predictable mathematical falsifiable

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.

Hey guys so i need to know what is _nh3+> nh4oh ~chemistry~