Atomic Symbols and Isotopes

1. 39 K 19 Atomic Symbols and Isotopes mass # neutrons + protons element Symbol atomic # protons # protons = # of electrons for a NEUTRAL atom 39 - 19 = 20 n0 How many neutrons are present? How many electrons are present? 19 e-

2. Complete the Table Below

3. Radioactivity • What is radioactivity? • Radioactivity occurs when an unstable nucleus spontaneously emits fragments of the nucleus and/or energy. Unstable Nucleus = Radioactive • Why are only some isotopes radioactive? • The ratio of protons to neutrons in the nucleus determines whether or not a nucleus is radioactive.

4. Depicting Nuclear Reaction For nuclear reactions, • the sum of the mass numbers (top numbers) and • the sum of the atomic numbers (bottom number) must be the same on both sides. Mass Numbers: 9 + 4 = 12 + 1 13 = 13  Atomic Numbers: 4 + 2 = 6 + 0 6 = 6 

5. Finding the Missing Nucleus Mass Numbers 234 = 4 + ? ? = 230 Atomic Numbers 90 = 2 + ? ? = 88

6. Finding the Missing Nucleus Mass Numbers 14 = 0 + A A = 14 Atomic Numbers 6 = -1 + Z Z = 7

7. Examples of Transmutation Reactions These are all transmutation reactions because the elements on the left side are changed to produce a different element on the right side.

8. Emissions from Radioisotopes A radioisotope is a nucleus that is radioactive or unstable.

9. Writing Nuclear Decay Equations Write the nuclear decay equation for the alpha decay of uranium-238. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 238 = 4 + ? ? = 234 Atomic Number: 92 = 2 + ? ? = 90

10. Writing Nuclear Decay Equations Write the nuclear decay equation for the beta decay of iodine-131. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 131 = 0 + ? ? = 131 Atomic Number: 53 = -1 + ? ? = 54

11. Writing Nuclear Decay Equations Write the nuclear decay equation the emission of a gamma ray from carbon-14. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 14 = 0 + ? ? = 14 Atomic Number: 6 = 0 + ? ? = 6

12. Examples of Transmutation Reactions These are all transmutation reactions because the elements on the left side are changed to produce a different element on the right side.

13. Decay Series for Uranium-238 This diagram shows the steps that an isotope of uranium takes to reach a stable isotope, lead-206.

14. A Closer Look at the Decay Series Write a nuclear decay equation for what we occur to uranium-234 according to this decay series.

15. A Closer Look at the Decay Series Write a nuclear decay equation for what we occur to lead-210 according to this decay series.

16. Writing Nuclear Decay Equations Write the nuclear decay equation for the alpha decay of uranium-238. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 238 = 4 + ? ? = 234 Atomic Number: 92 = 2 + ? ? = 90

17. Writing Nuclear Decay Equations Write the nuclear decay equation for the beta decay of iodine-131. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 131 = 0 + ? ? = 131 Atomic Number: 53 = -1 + ? ? = 54

18. Writing Nuclear Decay Equations Write the nuclear decay equation the emission of a gamma ray from carbon-14. Start your decay equation by writing the symbol for this nucleus and then follow it with an arrow. Write the symbol for the type of decay. Mass Number: 14 = 0 + ? ? = 14 Atomic Number: 6 = 0 + ? ? = 6

19. Protecting Ourselves from Radioactive Particles

20. Positive Uses of Nuclear Chemistry Nuclear Power Nuclear Medicine Kills Bacteria on Food