The Flame Test
A basic form of Emission
Spectroscopy
Ionic Bonding
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Anions and cations are held together by
opposite charges.
Ionic compounds are called salts.
Simplest ratio is called the formula unit.
The bond is formed through the transfer of
electrons.
Electrons are transferred to achieve noble gas
configuration.
Ionic Bonding
Na Cl
Ionic Bonding: Lewis Structure
+
Na
Cl
-
Ionic Bonding

All the electrons must be accounted for!
Ca
P
Ionic Bonding
Ca
P
Ionic Bonding
+2
Ca
P
Ionic Bonding
+2
Ca
Ca
P
Ionic Bonding
+2
Ca
Ca
P
-3
Ionic Bonding
+2
Ca
P
Ca
P
-3
Ionic Bonding
+2
Ca
P
+2
Ca
P
-3
Ionic Bonding
Ca
+2
Ca
P
+2
Ca
P
-3
Ionic Bonding
Ca
+2
Ca
P
+2
Ca
P
-3
Ionic Bonding
+2
Ca
+2
Ca
+2
Ca
P
P
-3
-3
Ionic Bonding
Ca3P2
Formula Unit
Properties of Ionic Compounds
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Crystalline structure.
A regular repeating arrangement of ions in the
solid.
Ions are strongly bonded.
Structure is rigid.
High melting points- because of strong forces
between ions.
You and Your Partner
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A test tube rack with 8 test tubes
Label, by metal, two splints for each test tube
Add salt solutions to separate test tube and
place labeled splints in appropriate test tube
Soak splints while we review the science behind
today’s lab
Insert wooden splint at tip of inner cone…do
not let it burn
Record color of flame
The Metals
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Sodium - NaCl
Potassium - KCl
Strontium - Sr(NO3)2
Copper - Cu(NO3)2
Lithium - LiNO3
Calcium - CaCl2
Barium - Ba(NO3)2...caution: POISON
Unknown: A, B, C or D
Emission Spectroscopy

Technique used to identify unknown elements in
a sample
Basis of Test
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Electrons in the ground state get excited when
energized
Excited electrons are unstable
Electrons fall back down to the ground state by
releasing energy
Energy takes the form of visible light
Line Spectrum
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Characteristic wavelengths (colors) of light are given off
by elements
These wavelengths are an elements line spectrum
Hydrogen
434
410 nm
nm
656 nm
486
nm
Flame Test
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Used to identify metals in solution
Electrons absorb energy from the flame to enter
the excited state
Safety
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Goggles and aprons
Double cone flame
Garbage in tin can
partially filled with water
Wash hands and lab
station