If the half-life of a radioactive substances is 590 million years and you have 40 atoms of it, how many half-lives will have passed when 5 atoms remain

Y=‐1x + 7 if y has a value of ‐24 what is the value of x?

How does a hydroelectric power plant converts energy into energy.

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.