1. Lec: Isotopes and Ions

2. An Isotope is an element that has the same number of protons but a different number of neutrons.

3. Example: C 12,C 13, and C 14 have 6 protons but 6, 7, and 8 neutrons. The combination of the # of protons and neutrons equals the isotope #.

4. The nuclei of C 12,C 13, and C 14 C 12 = 6 protons 6 neutrons C 13 = 6 protons7 neutrons C 14 = 6 protons 8 neutrons Protons= Neutrons= C 12 C 13 C 14

5. Determine what isotope is the atom below. Express you answer as an isotope number.

6. F 19 9 Protons and 10 neutrons

7. Ion: An atom that has an electrical charge due to the increase or decrease of electrons.

8. All protons have a +1 electrical charge. All electrons have a -1 electrical charge. If an atoms protons and electrons are the same the atom is neutral.

9. An ion with a negative (-) electrical charge is an anion. Examples of anions are expressed like this: F - or C -2 Fluorine (F) has gained an electron thus changing F to a (-1) electrical charge. Carbon (C) has gained two electrons thus changing the electrical charge to -2.

10. Example of an ion for F - Fluorine according to your PTE should have 9 electrons and protons however F - has 10 electrons and 9 protons.

11. An ion with a positive (+) electrical charge is an cation. Examples of cations are expressed like this: Li + or C +2 Lithium (Li) has lost an electron thus changing Li to a (+1) electrical charge. Carbon (C) has lost two electrons thus changing the electrical charge to +2.

12. Example of cation for Li + Lithium according to your PTE should have 3 electrons and protons however Li + has 2 electrons and 3 protons.

13. Lec: Types of Radioactive Decay and Half-Life Alpha Particle Decay Beta Particle Decay Gamma ray

14. Alpha Particle Decay A positively charged helium (He +2 ) nuclei traveling at a high speed.

15. Beta Particle Decay A negatively charged electron particle that travels at a high speed.

16. The mass of an alpha particle is almost 8000 times more than a beta particle.

17. Gamma Ray An electromagnetic wave similar to X-rays. It can not be detected by your eyes. Gamma rays move at the speed of light.

18. Half-Life: The time it takes for a radioactive isotope total mass to decay by one half. A half-life can be anywhere from fractions of a second to millions of years. Example: U 238 has a half-life over 4.5 billion years and Po 214 is 0.0000016 second.

19. The half-life of Ra 222 at the end of 0 half life. 100% still radioactive radon.

20. The half-life of Ra 222 at the end of 1 st half life. 50% still radioactive radon.

21. The half-life of Ra 222 at the end of 2nd half life. 25% still radioactive radon.

22. The half-life of Ra 222 at the end of 3rd half life. 12.5% still radioactive radon.

23. The half-life of Ra 222 at the end of 4 th half life. 6.25% is still radioactive radon.

24. Calculating the half-life of Ra 222. Ra 222 has a half-life of 4 days and starting mass of 800g. # of half lives Time% Radioactive Mass radioactive 0 1 2 3 4

25. 0 half life # of half lives Time% Radioactive Mass radioactive 00 days100800 g 1 2 3 4

26. 1 st half life # of half lives Time% Radioactive Mass radioactive 00 days100800 g 14 days50400 g 2 3 4

27. 2 nd half-life # of half lives Time% Radioactive Mass radioactive 00 days100800 g 14 days50400 g 28 days25200 g 3 4

28. 3 rd half-life # of half lives Time% Radioactive Mass radioactive 00 days100800 g 14 days50400 g 28 days25200 g 312 days12.5100 g 4

29. 4 th half-life # of half lives Time% Radioactive Mass radioactive 00 days100800 g 14 days50400 g 28 days25200 g 312 days12.5100 g 416 days6.2550 g

30. Bismuth, Bi 214 has a half-life of 20 minutes, how much will still be radioactive when it reaches its 4 th half-life and when will this occur? The starting radioactive mass is 200g.

31. 4 th half-life # of half lives Time% Radioactive Mass radioactive 00 minutes 100200 g 120 minutes 50100 g 240 minutes 2550 g 360 minutes 12.525 g 480 minutes 6.2512.5 g

32. The Last Lecture For This Unit.

33. Bismuth-210 # of half lives Time% Radioactive Mass radioactive 00 days10064 g 15 days5032 g 210 days2516 g 315 days12.58 g 420 days6.254 g