1. CHEM-TO-GO LESSON 6: ISOTOPES AND ATOMIC MASS CONVERSATION STARTER Materials: 1)Periodic table and Isotopes & Atomic Mass video notes 2)Unit 2 Practice Packet 3)Pencil and calculator

2. A Quick History Lesson Seven Significant Historical Figures: 1) Democritus (~ 400 BC) – “atomos” 2) Aristotle (~ 400 BC) – no “atomos” 3) John Dalton (early 1800s) - finally, yes to atoms 4) JJ Thomson (1800s) – Cathode Ray Experiment 5) Ernest Rutherford (1800s) – Gold Foil Experiment 6) Neils Bohr (1913) – Energy levels = planetary atom 7) Heisenberg, Schrodinger, etc. (1920s) = quantum mechanical model

3. Collaborative Synthesis Experience Review the definition and examples of isotopes in your video notes. Brainstorm with your partner, and develop your own analogy for isotopes. Be prepared to share your idea! In my video, I used Legos as an analogy for isotopes. Students will adapt knowledge to an unpredictable situation.

4. Collaborative Analysis Experience You have been given a sample of a new element, Dotium. The element was discovered by Emily Jones and Logan Blocksidge yesterday. 1)When scientists analyze a new element, they look for isotopes. Are all of the atoms of your sample identical to each other? If not, how many isotopes do you have? 2)When different isotopes have been found, scientists separate the isotopes in order to study them. Separate the isotopes of your Dotium sample. 3)Scientists measure the abundance of each isotope. How many atoms of each isotope do you have? How many total atoms of Dotium do you have? Calculate a percent abundance for each isotope. 4)After determining abundance, scientists find a mass for each isotope. Find the mass of each isotope of your Dotium sample. 5)Scientists then calculate the atomic mass to display on the periodic table. Calculate the mass of your Dotium sample. Students will apply knowledge to a real-world situation.

5. Collaborative Analysis Experience Students will apply knowledge to a real-world situation. DUE TODAY!

6. Collaborative Analysis Experience Students will apply knowledge to a real-world situation. When you have turned in your Candium Lab, please solve the “Atomic Mass Calculations Practice” from your practice packet. Please show your work on a separate sheet of paper. Use your video notes and class example to help you! ADVICE:  #2 doesn’t require any math.  #5 is really tough! I will help you with it if you can’t figure it out.