1. DO NOW:
70% of your grade in a class is based on tests, and 30% on HW. You average a score of 90 on tests, and 100 on HW. What is your grade in the class?

2. Whiteboard Review Draw a model of each of the hydrogen isotopes

4. Whiteboard REVIEW
Draw a Venn Diagram to compare and contrast Carbon-12 and Carbon-13
(Note both commonalities and differences)

5. Whiteboard REVIEW Give the chemical notation for the following atoms.
Example:
Give the chemical notation for the following atoms.
Nitrogen-15
Carbon-13
A sodium cation with a charge of +1
A sulfur anion with a charge of -2

6. Whiteboard REVIEW
A) A sample of silver is 30.72% Silver-107 and 69.28% Silver-108.
What is its average atomic mass/weight?

7. Chemical vs. Nuclear Reactions
Fill in the Venn Diagram after watching the video clip.
What else do you know about chemical reactions vs. nuclear reactions?
Chemical Reaction
Nuclear Reaction

8. Nuclear Stability
Most atoms have a stable nucleus not radioactive Protons are positively charged, and like charges repel.
Hmm…then why doesn’t the nucleus fly apart since all the protons are repelling each other???

9. Nuclear Stability
Another force, called the strong nuclear force is holding the nucleus together. Strong nuclear force = the force that helps to hold the nucleus together. It is different from forces we encounter in daily life

10. Nuclear Stability
Strong nuclear forces help to balance the electromagnetic repulsion that the positive protons experience. Electromagnetic forces and strong nuclear forces are constantly pitted against each other.

11. Nuclear Stability
Strong nuclear forces… …help to hold the nucleus together  act like glue in the nucleus

12. Nuclear Stability
Elements 1-20 neutrons = protons Beyond element 20 more neutrons needed in nucleus to glue nucleus together Beyond element 83 (bismuth)  no number of neutrons sufficient to glue the nucleus together indefinitely

13. Nuclear Stability
There are “magic numbers” of protons and neutrons (2, 8, 20, 28, 50, and 82) that are stable. Atoms with even number of protons and neutrons tend to be stable.

14. Radioactive Decay
Radioactive Decay: There are 3 types of radioactive decay.

15. Radioactive Decay (alpha decay)

16. Alpha Decay

17. Radioactive Decay (beta decay)

18. Beta Decay

19. Radioactive Decay (gamma decay)

20. Radioactive Decay (gamma decay)

22. Some more practice… Copy down problem into composition book
Some more practice… Copy down problem into composition book. Work with a partner to complete.