I need help ASAP this is my final

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.

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

What best discribes the relationship between wavelength and frequency in a electromagnetic wave