A radioactive isotope of potassium (K) has a half-life of 20 minutes. If a 163 gram sample of this isotope is allowed to decay for 30 minutes,
how many grams of the radioactive isotope will remain?

Explain why scientists use shared characteristics to make cladograms.

In 2002, the rare earth elements mine in mountain pass, california was closed because

Which factor is likely to impact the possible number of compounds? presence of unlimited number of elements in the periodic table the inability of atoms to align perfectly with other atoms the ability of all elements to react with every other element all elements being equally reactive