Transcript Power Point introduction

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
11p+
12 n0
Click here
to increase
the
energy!!!
Example of a Na atom:
Click here to
See Nature
stabilize the
atom!
11p+
12 n0
Example of a Na atom:
11p+
12 n0
Atom is now back to normal:
STABLE!
11p+
12 n0
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?