How can the type of rock provide information about the conditions that existed when the rock formed?

What semimetal can form four single covalent 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.

Which sample at stp has the same number of atoms as 18 liters of ne at stp