Name the element: 1s2 252 2p 3s2 3p6 453 3d9 O Strontium Sr
O Krypton Kr
O Tungsten W
O Copper Cu
Silver Ag
Silicon Si

What method(s) do plants use to obtain nitrogen? select all that apply. absorb it from the atmosphere use bacteria to convert nitrogen to usable form obtain usable nitrogen compounds from the soil absorb nitrogen from water taken in at the roots

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.

Stage in which a star’s outer layers have started to cool and grow outward?