Metal atom →
Metal ion
SO2 →
Color?
SO4²-
Colorless → Colorless
Fe²+ →
Color?
Fe³+
Pale green → Yellow
SO3²- →
Color?
SO4²-
Colorless → Colorless
H2 →
Color?
H+
Colorless → Colorless
I- →
Color?
I2
Colorless → Brown
C →
Color?
C → CO2
C → CO2
Black → Colorless