Color of Ions Lab

Visible Light A type of electromagnetic radiation Found on the electromagnetic spectrum The visible region is found in l from 400-750nm ROYGBIV

Visible Light In order for a compound to have color, it must absorb visible light

Visible Light The energy of electrons is quanitized which means they only exist at certain energy levels separated by specific intervals

Visible Light When atoms absorb energy in the form of electromagnetic radiation electrons jump to higher energy levels

Visible Light Then when they drop back down, they give off the energy in the form of electromagnetic radiation

Visible Light The energy difference between levels will predict what type of electromagnetic radiation so if a compound will absorbs visible light

Visible Light Because the energy level changes for the electrons of a particular atom are always the same, they can be identified by absorbtion spectra

Visible Light When a sample absorbs visible light, the color we perceive is the sum of the remaining colors that are reflected by an object

Compounds and Color For ions of Group I, II, and III, the energy difference is greater than the energy of visible light, so they are colorless.

Compounds and Color For most transition metal ions, the energy difference is much smaller, and these ions absorb visible light, so they have color

Compounds and Color Chloride, sulfate, and nitrate anions are all colorless, so their compounds are white.

Compounds and Color For the transition elements, the existence of colored cations is as characteristic as their different charges

Discussion Explain why some compounds are colored and others are colorless Define visible light What happens when an element gives off color Why are transition elements colored and groups 1A, 2A, and 3A colorless?