https://physlab-wiki.com/ 2026-04-15T02:22:33+00:00 https://physlab-wiki.com/ https://physlab-wiki.com/lib/tpl/UChicago/images/favicon.ico text/html 2023-06-09T10:25:16+00:00 Anonymous (anonymous@undisclosed.example.com) https://physlab-wiki.com/physicsdemos/demos-in-development/absorption-and-emission-spectroscopy-of-salts?rev=1686320716&do=diff Absorption and emission spectroscopy of salts Motivation This demo arises from my desire to synthesize and communicate the fact that emission and absorption spectra are two sides of the same coin. This is usually mentioned in textbooks in the form of a spectroscopy setup of light going through a gas and being emitted by the same gas, with their corresponding spectra (e.g. Figure 39.18 from the intro book from Young and Freedman). However, the truth of the matter is that, to my knowledge, this … text/html 2024-08-29T15:58:00+00:00 Anonymous (anonymous@undisclosed.example.com) https://physlab-wiki.com/physicsdemos/demos-in-development/alt_photoelectric?rev=1724961480&do=diff Another illustration of the photoelectric effect can be done with a neon lamp. They normally ionize atoms to glow, but only after a certain applied voltage. Tuning the supply voltage just shy of the turn-on point, you can use a light to knock electrons off the electrodes to jump-start the lamp.