1. Nuclear Chemistry

2. RadioactivityRadioactivity  The spontaneous decomposition of a nucleus to form a different nucleus accompanied by a release of energy or a particle OR  The spontaneous transformation of an unstable atomic nucleus into a stable product while emitting radiation

3. The Nucleus  The atomic nucleus is made up of protons and neutrons which are collectively called nucleons.  Nuclide – in nuclear chemistry the atom is referred to as the nuclide.

4. NuclidesNuclides  Nuclides are represented by two ways: Radium-228 (name of element followed by mass number, which is the # of protons + neutrons) 228 (mass number) Ra (symbol) 88 (atomic number which is the # of protons as well as the # of electrons) 1) 2)

5. 14 6 C the mass number is… 14 6 C the mass number is… 1.14 2.6 Answer: 14

6. 14 6 C the atomic number is… 1.14 2.6 Answer: 6

7. 14 6 C has _____ protons 1.6 2.14 3.8 Answer: 6

8. 14 6 C has _______ neutrons… 1.6 2.14 3.8 Answer: 8

9. 209 84 Po has _ neutrons and _ protons 1.209 N, 84 P 2.84 N, 209 P 3.125 N, 84 P 4.84 N, 125 P Answer: 125 N, 84 P

10. Cobalt – 60 has __neutrons and __ protons 1.27 P, 33 N 2.27 P, 60 N 3.60 P, 27N 4.60 P, 33N 5.60 P, 60 N Answer: 27 P, 33 N

11. Nuclear Reactions  Chemical reactions involve the breaking and forming of bonds between different atoms.  In a nuclear reaction the situation is different – in a nuclear reaction changes occur involving the number of protons, neutrons, or electrons in a single atom.

12. Nuclear Reactions  Proton is symbolized: 1 1 p  Electron is symbolized: 0 e 0 β  Neutron is symbolized: 1 0 n

13. Nuclear Equations  In nuclear equations the total of the atomic number and the total of the mass number must be equal on both sides of the equation. Example: 9 4121 Be+ He  C + n 4 2 60 Mass Number: 9+4 = 13 12+1 = 13 Atomic Number: 4+2 = 6 6+0 = 6  This is also called a transmutation reaction, because the beryllium-9 became carbon-12.

14. Practice: Complete the following nuclear equations: 1. 218 214 Po  + Pb 84 _________ 82 2. 253 4 256 Es+ He  Md + 99 2 101 ________ 3. 142142 Pm+  Nd 61 _________ 60

15. RadiationRadiation  Radiation comes from the nucleus of an atom.  Unstable nucleus emits a particle or energy  alpha  beta  gamma

16. A. Types of Radiation  Alpha particle (  )  helium nucleus paper 2+  Beta particle (  -)  electron 1-  Gamma (  )  high-energy photon 0 concrete lead Metal Foil

17. A. Types of Radiation  Alpha particle (  )  helium nucleus paper 2+ Alpha Emission – an alpha particle (  ) is 2 protons and 2 neutrons (or a helium atom) bound together and is emitted from the nucleus during some kinds of radioactive decay. 2102064 Po  Pb + He 84822 Paper or clothes will shield you from alpha particles.

18. B. Types of Radiation  Beta particle (  -)  electron 1- Metal Foil Beta Emission – a beta particle (  ) is an electron emitted from the nucleus when a neutron is converted to a proton. 110 n  p +  01-1 14140 C  N +  67-1 Metal foil will shield you from beta particles.

19. D. Types of Radiation  Gamma (  )  high-energy photon 0 concrete lead Gamma Emission – gamma rays (  ) are high-energy electromagnetic waves emitted from a nucleus as it changes from an excited state to a ground energy state. Very similar to light, but is much more dangerous. Gamma emission usually occurs immediately following other types of decay. Lead or concrete will protect you from gamma rays.

20. Practice: Identify and complete the following nuclear reactions: 1. 9 4  Be + He __________ 4 2 2. 234234 Th  Pa + 9091 ___________

21. Practice: Identify and complete the following nuclear reactions: 3. Write an equation to represent the decay of thorium-230 by alpha emission.

22. RadiationRadiation  Effects of Radiation - The effects of radiation depends on the amount and exposure. Massive doses can be deadly.  DNA molecules are sensitive to alpha, beta, positron, gamma, and x-rays.