Alchemy Unit – Investigation IV

1. Alchemy Unit – Investigation IV Lesson 1: Island of Stability

2. 63 197 Cu Au 29 79 Admit Slip • The isotope notation for an atom of copper and an atom of gold are given below. • How could you change a copper atom into a gold atom? • What would you need to change? Give specific numbers. • Why is this change called a nuclear reaction? Unit 1 • Investigation IV

3. 63 197 Cu Au 29 79 Isotope Review Top #: Mass Number • Copper-63 • 29 protons • 29 electrons • 63 – 29 = 34 neutrons Bottom #: Atomic Number (Number of protons) Gold-197 79 protons 79 electrons 197 – 79 = 118 neutrons Neutrons = mass - protons Unit 1 • Investigation IV

4. The Big Question • What is the range of the number of neutrons found in isotopes of various elements? Unit 1 • Investigation IV

5. Objective: Students will be able to determine how many neutrons are required to make a stable element with a given number of protons. Agenda: Admit Slip Homework Review Notes Classwork Exit Slip Grade Update Unit 1 • Investigation IV

6. Homework Review • 1. • They have different numbers of neutrons and different masses. • Fluorine-23: 9p 9e 14n : 27p 27e 32n Mo-96: 42p 42e 54n 3. a) The mass is 58 amu. b) Unit 1 • Investigation IV

7. Homework Review • a) Atomic Mass = 30.97 • b) Atomic Number = 15 • c) Phosphorus-31 will be more abundant because 30.97 is closest to 31. Unit 1 • Investigation IV

8. Atom Stability 9 / 26 / 13 • Nuclear chemistry is the study of the nucleus of the atom. • The band of stability is the range in the number of neutrons for a given number of protons for stable isotopes that are found in nature. • Atoms that exist for a long time are referred to as stable. Unit 1 • Investigation IV

9. Radioactive elements are unstable because they decay over time as pieces of the nucleus break apart. • Radioactive atoms break down into other elements. • Any isotope that is around long enough to be detected and measured qualifies as an element, but still can be highly unstable and radioactive. Unit 1 • Investigation IV

10. Activity • Purpose:Some combinations of neutrons, electrons, and protons are not stable enough to be called elements. This lesson shows you how to predict the numbers of neutrons, electrons, and protons of the isotopes they are likely to find in nature. (cont.) Unit 1 • Investigation IV

11. Unit 1 • Investigation IV

12. (cont.) (cont.) Unit 1 • Investigation IV

13. Making Sense • What kind of generalization can you make about how the number of protons and neutrons are related to each other in the elements? Unit 1 • Investigation IV

14. Exit Slip • Use your graph to determine how many neutrons you would need to make a stable element with 75 protons. Unit 1 • Investigation IV

15. Wrap-Up • In order for an atom to be considered an element, it has to have a stable nucleus and exist long enough to be detected. • The neutron to proton ratio is an important factor in determining the stability of a nucleus. • Some isotopes are more stable than others. Unstable isotopes undergo nuclear decay to produce atoms with lower mass. Unit 1 • Investigation IV