The NRC and the general scientific community believe that underground salt mines will provide safe nuclear storage for. (Options:)
a. hundreds of years
b. a lifetime
c. thousands of years

Iam pretty sure that the answer is d

They have mobile charged particles.  i hope this : )good luck!

Answerapothecary> ok i believe this is the answer, but plz check first/ good luck

Answer: 1s²  2s²  2p⁶explanation: from the periodic table, we can note that the neutral fluorine  has 9 electrons (symbol is shown in the attached image)therefore, the configuration of neutral fluorine  is: 1s²  2s²  2p⁵now, f⁻  means that the neutral fluorine  gained one extra electron. this means that f⁻  has 10 electrons.the extra electron will occupy the 2p level to make it complete.the configuration now  is: 1s²  2s²  2p⁶comparing between both f and f⁻, we can note that f⁻  has now complete orbitals which means that it is more stable than f based on lewis postulatehope this : )