How do you delete your account just wondering cuz ima make a new one

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.

Which of these is a physical property

Areaction is first order with respect to reactant x and second order with respect to reactant y. which statement describes the rate law for this reaction?