Except for elements 1 and 2, all other elements are stable with how many electrons in their outermost (valence) energy level? except for elements 1 and 2, all other elements are stable with how many electrons in their outermost (valence) energy level? 2 8 18 32

At a certain temperature the rate of this reaction is first order in hi with a rate constant of : 0.0632s2hig=h2g+i2g suppose a vessel contains hi at a concentration of 1.28m . calculate how long it takes for the concentration of hi to decrease to 17.0% of its initial value. you may assume no other reaction is important. round your answer to 2 significant digits.