Atomic Structure and The Periodic Table p 143

Atomic Structure and The Periodic Table

p. 143 12/10 Flame Test QOTD Explain how chemists can state with certainty that no one will discover an element between sulfur (S) and chlorine (Cl). Answer: Chlorine has an atomic number one greater than sulfur. This means it has one more proton in its nucleus. Each element is defined by its atomic number, which is a positive integer.

After Reading Background Information Example of a Na atom: Increase in NRG causes electrons to jump to next higher shell 11 p+ 12 n 0 Click here to increase the energy!!!

Example of a Na atom: Click here to See Nature stabilize the atom! 11 p+ 12 n 0 Now the UN atom STA BLE is

Example of a Na atom: 11 p+ 12 n 0

Atom is now back to normal: STABLE! 11 p+ 12 n 0

p. 140 12/10 Flame Test Purpose: Write what the purpose for the lab is… Materials: Bunsen burner flint striker or matches Water soaked wood splint 6 unknown metals (salts) from Group I & II

p. 140 12/10 Flame Test Procedure: 1. Light Bunsen Burner so it has a low hot flame 2. Soak 6 wood splints in distilled water (Done for you) 3. Dip one wood splint into the container of a substance collecting a small amount of substance on the end of the wood splint 4. Carefully pass the wood splint through the flame 5. Observe the color the flame changes; record the color in the table 6. Repeat steps 3 through 5 for each substance three times each 7. Clean lab station when finished 8. Return to your desk and get a sheet from the instructor to identify each unknown substance 9. Answer the conclusion questions

p. 141 12/10 Flame Test Data Table: Unknown substance 1 2 3 4 5 6 Trial 1 Trail 2 Trial 3 Unknown substance Name

p. 141 12/10 Flame Test Conclusion Questions: Answer in complete sentences or be deducted 10%. 1. What inaccuracies (errors) may be involved in using flame test for identification purposes? 2. Explain how difficult or easy it was to decide what elements were in the unknown substances using your results. 3. Explain why identification of a substance with only one property is valid or invalid. 4. Explain how the colors observed in the flame tests are produced? Be specific. 5. The energy of colored light increases in the order of red, yellow, orange, green, blue, and violet. List the metallic elements used in the activity in order of increasing energy emitted (lowest to highest). 6. Why do you think the chemicals have to be heated in the flame before the colored light is emitted?