emission lines
- Turn on mercury (Hg) gas
- Used in some street lamps and bright stadium lamps
- many blue lines
- wavelengths (colors) characteristic of Hg atom
- bluish color
- Neon (Ne)
- used in flashing commercial signs
- lots of red lines
- characteristic of the Ne atom
- give it a reddish hue
- Helium (He)
- very simple atom -- 2 electrons orbiting 2 protons & 2 neutrons
- used in He baloons (i.e. Goodyear blimp)
- one bright line plus several others
- He spectrum unique -- distinct from Ne and Hg