Cell membranes are said to be selectively permeable. which statement best explains what selectively permeable means?

Both josef loschmidt and amedeo avogadro contributed to our understanding of basic molecular numbers, sizes, and reaction ratios. neither scientist discovered “avogadro’s number” in the form we use it today (6.02 x 10 23). still, there’s a controversy over the name. research the contributions from these two scientists and read about how avogadro’s number got its name. briefly state what you think this number should be called, providing key details of each scientist’s contributions to this concept and a solid rationale for your case in naming the number.

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 the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering