Pls help me on my quiz for chemistry

How are elements arranged in a periodic table

How can one make a supersaturated solution? (apex)

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.