1. Agenda: 2/19 Warm-up: Origin of the Elements
Review of Radioactive Isotopes
Half Life Calculations
Fission and Fusion
Mole Practice

2. Review: Isotopes What does the “235” in Uranium-235 mean?
What is another way to represent the isotope Uranium -235?
How do Carbon-12 and Carbon-14 differ?

3. Review: Radioactive Isotopes
A radioactive isotope has an __________nucleus that undergoes _____________ changes.
Emits particles 1. 2.
Emits energy in the form of __________ waves.
Transmutates (changes) into another element

4. Fill in the missing symbols & identify the type of particle emitted

5. Answers

6. Write a balanced nuclear equation for each decay process indicated.
a. The isotope Th-234 decays by an alpha emission.
b. The isotope Fe-59 decays by a beta emission

7. Answers

8. Half life Calculations
How much of a 100g sample of an unstable isotope remains after 25 years if the half life is 5 years?
Determine how many “half life intervals”.
Calculate the amount of original sample remaining after each ½ life
Simplify the calculations
100g

9. Half Life Problems
How much of a 60g sample of an unstable isotope remains after 2 days if the half life is 12 hours?
7.5 g

10. Half Life Problems
How much of a 20 g sample of an unstable isotope remains after 3 sec if the half life is 0.5 seconds?

11. Nuclear Fission – Example: Catawba Nuclear Energy Plant – Lake Wylie
For Student notes:

12. Nuclear Fusion Example: Sun’s (Star’s) Energy

13. Origins of Element
Reading Analysis:

14. Teachers' Domain: The Origin of the Elements

15. Teachers' Domain: The Elements: Forged in Stars

16. Moles: a counting unit in chemistry
Mole calculation review & practice
Molar Mass of Compounds

17. Mole Flow Chart
Gas volume
Mass
Mole
Atoms Compounds

18. Practice problems: Moles and Mass
What is the mass of 0.5 moles of S?
How many grams is equivalent to moles of Fe?
4.63 mol P = ? grams P

19. Practice problems How many moles are in 84.3 grams of Si?
50 grams of Ne = ? moles of Ne

20. Mole and Atom Conversions
How many atoms of Al are in 2.5 moles?
How many atoms of Ag are in 0.26 moles?
How many atoms of He are in moles?

21. Moles and Volume (Gases only)
How many Liters of He are in moles?
How many moles are in 60 L of Neon?

22. Molar Mass of Compounds
NaOH H₃PO₄
H₂O PCl₃
MgCl₂ H₂SO₄

23. Mole Conversion of Compounds
How many grams are in 5 moles of CO₂?
How many atoms are in 5 moles of CO₂?
How many liters are in 5 moles of CO₂?