Why is carbon able to form so many compounds?

carbon atoms can bond to each other to an extent not possible for other elements.
carbon atoms can only form chains.
carbon atoms can only form rings.
carbon atoms can only form single bonds.

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.