How many days are required for 200. grams of radon-222 to decay to 50.0 grams?
(1) 1.91 days (3) 7.64 days(2) 3.82 days (4) 11.5 days

Temperature and kinetic energy are proportional. a) adirectly b) directly c) indirectly

Two things that biomedical has invented or innovated

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.