Asample of the radioisotope potassium-40 is crushed to increase its surface area. the temperature of the sample is then lowered 25°c. what affect do these changes have on the rate of nuclear decay? a.)the decay rate doubles b.)the decay rate decreases by half c.)the decay rate increases by half d.)the decay rate does not change

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.