1. Nuclear Chemistry

2. The Atom The atom consists of two parts: 1. The nucleus which contains: 2. Orbiting electrons. protons neutrons

3. X A Z Mass number Atomic number Element symbol = number of protons + number of neutrons = number of protons

4. U 235 92 U 238 92 There are many types of uranium: Mass # Atomic # Number of protons Number of neutrons Mass # Atomic # Number of protons Number of neutrons 235 92 143 146 92 238

5. Same number of protons but different number of neutrons is an….. ISOTOPE

6. Most naturally occurring isotopes are stable.

7. Atoms want to be stable

8. Determined by ratio of p + to n 0 Nucleus Stability

9. Radioactive Decay (radioactivity) Unstable nuclei decomposes into stable nuclei Half- Life is the time it takes for this decay to occur.

10. Click Link to View Video: https://www.dropbox.com/s/0c380hppk60ikz1/Nuclear%20Half%20Life_%20Calculations.mp4?dl=0

11. Half Life: Time for half of the radioactive nuclide to decay 1.How much of a 100. g sample of 198 Au is left over 8.10 days if its half-life is 2.70 days?

12. 2. A 50.0 g sample of 16 N decays to 12.5 g in 14.4 seconds. What is the half-life?

13. 3. The half life of 42 K is 12.4 hours. How much of a 750g sample is left over after 62.0 hours?

14. 4. What is the half-life of 99 Tc if a 500 g sample decays to 62.5g in 639, 000 years?

15. 5. There are 5.0 g of Iodine -131 left after 40.35 days. How many grams were in the original sample if its half-life is 8.07 days?

16. an alpha particle (  ), a beta particle (  ), or a gamma ray  Radioactive Decay emits:

17. When an unstable atom creates an alpha particle. Alpha particle is identical to that of a helium nucleus. It contains two protons and two neutrons. Alpha Decay He 4 2

18. Alpha Decay Ra 226 88 Rn 222 86 He 4 2

19. X A Z Y A - 4 Z - 2 + He 4 2 Alpha Decay unstable atom more stable atom alpha particle

20. Alpha Decay Ra 226 88 + He 4 2 Th 230 90 U 234 92 Th 230 90 + He 4 2 + Pb 214 82 He 4 2 Po 218 84

21. Beta Decay Beta particle is a fast moving electron created when a n 0 changes into a p + & e - When an unstable atom creates a beta particle.

22. Beta Decay Po 218 84  0 At 218 85

23. X A Z Y A Z + 1 +  0 Beta Decay unstable atom more stable atom beta particle

24. Beta Decay Bi 210 83 Po 210 84 +  0 -1 Pb 210 82 Tl 210 81 +  0 Pa 234 91 Th 234 90 +  0

25. Gamma Decay Not a charged particle it is energy, it’s a photon. Electromagnetic radiation with high frequency

26. Draw the correct wave

27. Symbol CompositionRangeShield Alpha Particle He or α Helium nucleus Beta Particle Gamma Ray short Paper, skin

28. Symbol CompositionRangeShield Alpha Particle He or α Helium nucleus Beta Particle e - or β Electron Gamma Ray short Paper, skin Heavy Clothing, glass, light metals, plastic

29. Symbol CompositionRangeShield Alpha Particle He or α Helium nucleus Beta Particle e - or β Electron Gamma Ray  Photons (electromagnetic spectrum) short Paper, skin Heavy Clothing, glass, light metals, plastic Long Lead or concrete