1 / 25

Isotopes

Isotopes. Isotopes of chlorine 35 Cl 37 Cl 17 17. chlorine - 35. chlorine - 37. Hyphen notation. Put the mass number after the name of the element carbon - 12 carbon - 14 uranium - 235. Isotopes. Chlorine-37 atomic #: mass #: # of protons: # of electrons: # of neutrons:.

rsosa
Download Presentation

Isotopes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Isotopes Isotopes of chlorine 35Cl 37Cl 1717 chlorine - 35 chlorine - 37

  2. Hyphen notation • Put the mass number after the name of the element • carbon - 12 • carbon - 14 • uranium - 235

  3. Isotopes • Chlorine-37 • atomic #: • mass #: • # of protons: • # of electrons: • # of neutrons: 17 37 17 17 20

  4. 9 10 9 9 19 • Find the • number of protons • number of neutrons • number of electrons • Atomic number • Mass Number 19 F 9

  5. 35 45 35 35 80 • Find the • number of protons • number of neutrons • number of electrons • Atomic number • Mass Number 80 Br 35

  6. if an element has an atomic number of 34 and a mass number of 78 what is the • number of protons • number of electrons • number of neutrons • complete nuclear symbol 34 34 44 78 Se 34

  7. if an element has 91 protons and 140 neutrons what is the • Atomic number • Mass number • Number of electrons • Complete symbol 91 231 91 231 Pa 91

  8. if an element has 78 electrons and 117 neutrons what is the • Atomic number • Mass number • number of protons • Complete symbol 78 195 78 195 Pt 78

  9. An atom of zinc has a mass number of 65. A. Number of protons in the zinc atom 30 B. Number of neutrons in the zinc atom 35 What is the mass number of a zinc isotope with 37 neutrons? 67

  10. 16 O 8 Write the nuclear symbols for atoms with the following: A. 8 p+, 8 n, 8 e- B. 17p+, 20n, 17e- C. 47p+, 60 n, 47 e- 37 Cl 17 107 Ag 47

  11. An atom has 14 protons and 20 neutrons. A. It has atomic number 14 B. It has a mass number of 34 C. The element is Si D. Another isotope of this element would be 36X 14

  12. Calculating averages • You have five rocks, four with a mass of 50 g, and one with a mass of 60 g. What is the average mass of the rocks? • Total mass = 4 x 50g + 1 x 60g = 260g • Average mass = 4 x 50g + 1 x 60g = 260g 5 5

  13. Avg. Atomic Mass Average Atomic Mass • weighted average of all isotopes • decimal numbers on the Periodic Table • round to 2 decimal places

  14. Average Atomic Mass • Is not a whole number because it is an average.

  15. Avg. Atomic Mass Average Atomic Mass • EX: Calculate the avg. atomic mass of oxygen if its abundance in nature is 99.76% 16O, 0.04% 17O, and 0.20% 18O. 16.00 amu

  16. Avg. Atomic Mass Average Atomic Mass • EX: Find chlorine’s average atomic mass if approximately 8 of every 10 atoms are chlorine-35 and 2 are chlorine-37. 35.40 amu

  17. Average Atomic Mass • Magnesium has three isotopes: 78.99% magnesium - 24 with a mass of 23.9850 amu, 10.00% magnesium - 25 with a mass of 24.9858 amu, and the rest is magnesium - 26 with a mass of 25.9826 amu. What is the average atomic mass of magnesium? • If not told otherwise, the mass of the isotope is the mass number in amu 24.30 amu

  18. Atomic Mass • Calculate the atomic mass of copper if copper has two isotopes. 69.1% has a mass of 62.93 amu and the rest has a mass of 64.93 amu. 63.55 amu

  19. Learning Check Gallium is a metallic element found in small lasers used in compact disc players. In a sample of gallium, there is 60.2% of gallium-69 (68.9 amu) atoms and 39.8% of gallium-71 (70.9 amu) atoms. What is the atomic mass of gallium?

  20. Solution Ga-69 68.9 amu x 60.2 = 41.5 amu for 69Ga 100 Ga-71 70.9 amu x 39.8 = 28.2 amu for 71Ga 100 Atomic mass Ga = 69.7 amu

  21. Finding An Isotopic Mass A sample of boron consists of 10B (mass 10.0 amu) and 11B (mass 11.0 amu). If the average atomic mass of B is 10.8 amu, what is the % abundance of each boron isotope?

  22. Assign X and Y values: X = % 10B Y = % 11B Determine Y in terms of X X + Y = 100 Y = 100 - X Solve for X: X (10.0) + (100 - X )(11.0) = 10.8 100 100 Multiply through by 100 10.0 X + 1100 - 11.0X = 1080

  23. Collect X terms 10.0 X - 11.0 X = 1080 - 1100 - 1.0 X = -20 X = -20 = 20 % 10B - 1.0 Y = 100 - X % 11B = 100 - 20% = 80% 11B

  24. Learning Check Copper has two isotopes 63Cu (62.9 amu) and 65Cu (64.9 amu). If the average atomic mass of Cu is 63.55 amu, what is the % abundance of each copper isotope?

  25. Solution 62.9X + 6490 - 64.9X = 6355 -2.0 X = -135 X = 67.5 %

More Related