The group number on the periodic table is the same as the positive charge for Group of answer choices

1.halogens

2.noble gases

3.alkali-metals

4.transition metals

One of the following properties was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version. which property fits this description?

An electrons position cannot be known precisely only it's probability of being in a certain location can be known

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.