Why would extracting copper be too expensive

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

Ineed ! i have no clue how to do this problem.

Polar bears give birth and hunt on sea ice. which of the following would polar bears survive during the melting of arctic ice? growing another layer of fur during summer migrate inland to search for different food sources staying put until the ice refreezes sticking to the usual diet of seals