If 3.125% of a sample remains how many half lives have passed

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom

Ithink that’s it’s b

Qand k are only the same when the forward rate of the reaction has reached zero.