Convert a 75.5G sample of MgO into moles of MgO

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.

An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons

What metric units would you use to measure the thickness of a key