[cs_content][cs_section parallax=”false” separator_top_type=”none” separator_top_height=”50px” separator_top_angle_point=”50″ separator_bottom_type=”none” separator_bottom_height=”50px” separator_bottom_angle_point=”50″ style=”margin: 0px;padding: 45px 0px;”][cs_row inner_container=”true” marginless_columns=”false” style=”margin: 0px auto;padding: 0px;”][cs_column fade=”false” fade_animation=”in” fade_animation_offset=”45px” fade_duration=”750″ type=”1/1″ style=”padding: 0px;”][cs_text]The Chemistry of Art > 2. The Structure of the Atom and Colours > The Relationship Between Absorption And Reflectance Spectra >[/cs_text][cs_text style=”color: #800000;font-family: “Oxygen”,sans-serif;”]The relationship between absorption and reflectance spectra and the effect of infra-red and ultraviolet light on pigments including zinc oxide and those containing copper[/cs_text][cs_text]Relationships:
- Absorption:
- Appears as black spectral lines within full spectrum
- Percentage of light absorbed at each wavelength
- Signifies which photons have been observed and hence which frequencies of visible light have been absorbed
- Reflectance:
- Percentage of light reflected at each wavelength
- Substance exhibits colour complementary to that color of absorbed particular wavelength.
Effects of Infra-red (IR) lights on selected compounds/substances:
- Zinc oxide changes from white to lemon yellow (returns after cooling)
- Red Copper (I) oxide changes to black Copper (II) oxide
(permanent change due to substance breakdown)
Effects of Ultraviolet (UV) on selected compounds/substances:
- Zinc oxide (ZnO) fluoresces as pale yellow under the presence of UV light
- Green malachite (CuCO3 . Cu(OH)2 ) fluoresces dirty mauve colour
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