In each of the following pairs, circle the species with the larger atomic or ionic radius: (a) Mg or Ba
(b) S or S2-
(c) Cu+2 or Cu
(d) He or H-
(e) Na or Cl

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.