Question 8 (2 points)
Which atom in each grogp (I and II) has the smallest atomic radius?
(1) Ca, Ti, Br
(II) O, S, Se
OC) Br; o
OD) Br; Se
O A) Ca; o
OB) Ca; Se
Question 9 (2 points)
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The chemical composition of soil varies with depth. an article in communications in soil science and plant analysis describes chemical analyses of soil taken from a farm in western australia. fifty specimens were each taken at depths 50 and 250 cm. at a depth of 50 cm, the average no3 concentration (in mg/l) was 88.5 with a standard deviation of 49.4. at a depth of 250 cm, the average concentration was 110.6 with a standard deviation of 51.5. find a 95% confidence interval for the difference in no3 concentrations at the two depths.