Name Section Period 16 Exercises: Ionizing Radiation 1) Forming stable nuclei The circled portion of the stable nuclei graph to the left is enlarged below. The curved line of dark squares represents stable nuclei. If a nucleus does not lie on the curved line, it is unstable. The unstable nuclei in this example will change protons into neutrons or neutrons into protons until they become a stable nucleus. a) The stable isotopes of calcium are: Calcium-40 (20 Ca), Calcium-42 (26 Ca), Calcium-43 (25 Ca), Calcium-44 (20 Ca), Calcium-46 ( 20 Ca), and Neutron 20 Ca Number N Calcium-48 (20 Ca). Darken the squares on the grid that represent these stable isotopes. b) Mark an X in the square that represents the nucleus of Silicon-40 (14 Si ) c) Silicon-40 nuclei last only a few seconds. Would silicon-40 become more stable by changing a proton into a neutron or a neutron into a proton? e) Draw a dotted line showing how the box representing Silicon- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 40 would change position on the Proton Number Z chart as the nucleus turns into a stable nucleus. 2) Nuclear reactions The nuclei below are unstable. For each nuclei, indicate whether the nucleus would become more stable by emitting an a, B" , or BY. Explain your answer. a) 180 (Oxygen-14) b) 292 U (Uranium-238) c) 10 Ne (Neon-23) The Ohio State University, 2015 7 1/10/15