Lecture 2 362 January 16, 2019
Paradigm Shift:
Development of Current
Atomic Theory—
Spectroscopy and Energy
Levels in Atoms
OR,
“Show me the Electrons!”
,Color Metal Flame Colors
Carmine: Lithium compounds. Masked by barium or sodium.
Red Scarlet or Crimson: Strontium compounds. Masked by barium.
Yellow-Red: Calcium compounds. Masked by barium.
Sodium compounds, even in trace amounts. A yellow flame is not
Yellow indicative of sodium unless it persists and is not intensified by
addition of 1% NaCl to the dry compound.
White White-Green: Zinc
Emerald: Copper compounds, other than halides. Thallium.
Blue-Green: Phosphates, when moistened with H2SO4 or B2O3.
Green
Faint Green: Antimony and NH4 compounds.
Yellow-Green: Barium, molybdenum.
Azure: Lead, selenium, bismuth, CuCl2 and other copper
compounds moistened with hydrochloric acid.
Blue
Light Blue: Arsenic and come of its compounds.
Greenish Blue: CuBr2, antimony
Potassium compounds other than borates, phosphates, and
silicates. Masked by sodium or lithium.
Violet
Purple-Red: Potassium, rubudium, and/or cesium in the presence
of sodium when viewed through a blue glass.
, Atomic Emission (Spectroscopy)
• An emission spectrum requires first the addition of
energy to a material.
• The addition of energy promotes electrons of that
material from the ground state to the excited state.
• As the electrons “fall” from the excited state to the
ground state, they emit the energy they absorbed in
the form of electromagnetic radiation (heat, light, etc.)
Comments
• Atomic emission is used in street lamps, fluorescent lights, and neon signs.
• Two common street lamps using this are the mercury lamp and the sodium lamp.
• “Neon” signs frequently implement the emission spectra of other gases such as
argon and krypton.
• Very sophisticated instrumental techniques such as “flame photometry” and
“atomic absorption” are based on the principles of atomic emission.
Paradigm Shift:
Development of Current
Atomic Theory—
Spectroscopy and Energy
Levels in Atoms
OR,
“Show me the Electrons!”
,Color Metal Flame Colors
Carmine: Lithium compounds. Masked by barium or sodium.
Red Scarlet or Crimson: Strontium compounds. Masked by barium.
Yellow-Red: Calcium compounds. Masked by barium.
Sodium compounds, even in trace amounts. A yellow flame is not
Yellow indicative of sodium unless it persists and is not intensified by
addition of 1% NaCl to the dry compound.
White White-Green: Zinc
Emerald: Copper compounds, other than halides. Thallium.
Blue-Green: Phosphates, when moistened with H2SO4 or B2O3.
Green
Faint Green: Antimony and NH4 compounds.
Yellow-Green: Barium, molybdenum.
Azure: Lead, selenium, bismuth, CuCl2 and other copper
compounds moistened with hydrochloric acid.
Blue
Light Blue: Arsenic and come of its compounds.
Greenish Blue: CuBr2, antimony
Potassium compounds other than borates, phosphates, and
silicates. Masked by sodium or lithium.
Violet
Purple-Red: Potassium, rubudium, and/or cesium in the presence
of sodium when viewed through a blue glass.
, Atomic Emission (Spectroscopy)
• An emission spectrum requires first the addition of
energy to a material.
• The addition of energy promotes electrons of that
material from the ground state to the excited state.
• As the electrons “fall” from the excited state to the
ground state, they emit the energy they absorbed in
the form of electromagnetic radiation (heat, light, etc.)
Comments
• Atomic emission is used in street lamps, fluorescent lights, and neon signs.
• Two common street lamps using this are the mercury lamp and the sodium lamp.
• “Neon” signs frequently implement the emission spectra of other gases such as
argon and krypton.
• Very sophisticated instrumental techniques such as “flame photometry” and
“atomic absorption” are based on the principles of atomic emission.
