The halflife of iron-52 is 7 minutes. What percent of the original sample is left after 28 minutes? 50%
25%
12%
6.5%

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