SPARK 1. Write the nuclear equations for the following: Gold-185 decays by ejecting an alpha particle. Uranium-233, alpha decay Gd-149 decays by losing a helium nucleus. Thorium-232 goes through alpha decay Beta decay of gold-201 2. Polonium-210 has a half-life of 138 days. How much of the isotope is remaining after 176 days if the starting amount was 66 mg? 3. Compared to the atoms of nonmetals in Period 3, the atoms of metals in Period 3 have: fewer OR more valence electrons? AGENDA 1) SPARK 2) SHARE OUT 3) LESSON 4) CLASS WORK 5) WRAP UP

Puzzler! Radioactive Emission Trends? Isotope Emission most likely to emit 3H -1e 14C 150Pm 4 2He 225Fr 60Fe 270L 17O What’s the pattern? Where’s your evidence? AGENDA 1) SPARK 2) SHARE OUT 3) LESSON 4) CLASS WORK 5) WRAP UP

DECAY TRENDS Elements whose atomic numbers are greater than 83 have no known stable isotopes. Elements with atomic numbers greater than 83 tend to undergo alpha decay, whereas elements with atomic numbers less than 83 tend to undergo beta decay. AGENDA 1) SPARK 2) SHARE OUT 3) LESSON 4) CLASS WORK 5) WRAP UP

DECAY SERIES GRAPH More than one step to become stable nuclide = map out transmutations! We can then look for patterns to understand the reactions easier. AGENDA 1) SPARK 2) SHARE OUT 3) LESSON 4) CLASS WORK 5) WRAP UP

LET’S PRACTICE TOGETHER Alpha decay of Thorium-232. Beta decay of Radium-228. Beta decay of the daughter nucleus of the previous question (#1b.) AGENDA 1) SPARK 2) SHARE OUT 3) LESSON 4) CLASS WORK 5) WRAP UP