Half life is the amount of time it takes for half of a sample to decay. how does the knowledge that , radioactive elements decay one atom at a time support the accepted definition of half life?

When the ionic compound nabr dissolves in water, br– ions are pulled into solution by the attraction between what two particles? a. the na+ and br– ions b. the na+ ion and the negative end of a water molecule c. the br– ion and the positive end of a water molecule d. the br– ion and the negative end of a water molecule