1) Define what is meant by the half - radioactive material. 2) Radioactive decay is a random process. Explain what this means.
3) The activity of radioactive sample is measured. The activity corrected for background radiation is found to be 240 Bq. The activity is measured again after 1 hour 30 minutes and is now 30 Bq. What is the half life of the sample?

Amoving company collects data about couches they move and displays the data in a table. the force along the ramp, the angle of the ramp, and the height the couch is raised to are shown. which statements correctly compare the work done to move the couches? check all that apply. the same amount of work is done for couches 1 and 3. the same amount of work is done for couches 2 and 3. the work for couch 1 is greater than the work for couch 2. the work for couch 2 is less than the work for couch 3. the work for couch 3 is greater than the work for couch 1. the work for couch 2 is greater than the work for couch 1.