What did ancient astronomers not know about eclipses?

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.

What is the lowest number energy level where a d sublevel is found

In which region is the substance in both the solid phase and the liquid phase? 1 2. 3 4 mark this and return save and exit next