Assume you have a radioactive spill of 9tc and you are measuring it using a large volume gm tube detector in the shape of a flat disc. you measure 1 counts per minute at a distance of 1 cm from the contaminated surfac a. what detection geometry will you assume for your calculation? b. what is your estimate of the counting efficiency of this geometry? c. what is the activity of the spill? d. if it was decided to leave it there without cleaning it off the surface, how long would it be before the activity was indistinguishable from background radiation of 25 counts per second (assuming it would be within 2 standard deviations of background)? how dangerous is this spill?

According to social exchange theory, altruistic behaviors benefit the individual who performs them. t/f

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final