Answer Happy

c) Half life is one of the activity of radioactive material which it is the time needed for half of the radioactive nuclei to decay. Figure 3 shows the graph for radioactive material activity. Count rate in counts per minute 350 300 250 200 150 100 50 0 Referring to Figure 3, 05 10 15 20 25 30 35 Time in days Figure 3 i) state the half life for that radioactive material. 40 45 iii) define the rate of radioactive materials left after 35 days. [2 marks] ii) define how long does it take for the activity of the radioactive material to fall to one quarter of its initial value. [2 marks] [2 marks]