how many red beads would be equal to 6.2 blue stars. 14 yellow shells=7.3 red beads 2.8 blue stars= 4.4 yellow shells

Can someone me with questions 15 to 17 plz.

What substance has a mass of 9.5g and volume of 2.1cm^3

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.