The activity of a medical radioisotope sample is measured as 1200 MBq1200\text{ MBq}1200 MBq.
This initial measurement is plotted as a point at (0,1200)(0, 1200)(0,1200) on the graph grid in Figure 1.
The half-life of this isotope is 6 hours.
Use this information to plot three more points on the grid in Figure 1 to show how the activity of the isotope changes over a period of 18 hours.
