which loses its outermost electrons more easily: bromine, br, or krypton, kr?

 it is easier for bromine to loses it outermost electron more readily than a krypton to do so,  a  bromine is a halogen, a strong non-metal that ideally will accept an electron to attain configuration .

 while a krypon is an inert gas, a nobles gasses do not  accept or reject electrons, it non reactive. therefore  even though the krypton is non-reactive , it is easily for it to accept releases an electron than for a bromine to release an electron.