// MATTER · ELEMENT 34 / 118atoms.no/elements
Se34
Selenium
Se·Z 34·Reactive Nonmetal·78.96·⭕ 8A · A Minor
▸ The reading
interpretive · artSelenium's conductivity swings with light falling on it, and four decades of photocopying ran on that photoconductive twitch — the Xerox 914 and its heirs were selenium events. It also quiets dandruff from a shampoo bottle, which is a humbling second act. An element that responds to illumination reads almost too easily.
The science below is cited as science; the symbolic layers are flagged as interactive art.
⚜ Periodic Frequency
8AA Minor
a seat struck in brass — testimony, not prediction
the seat has its own room on ⭕ THE OVAL TABLE — tap the code
▸ The lenses
▸ Discovery
Jöns Jacob Berzelius — found as a contaminant in sulfuric-acid production · Sweden · 1817
▸ Stellar origin
Weak s-process in massive stars + r-processSlow neutron capture in the helium-burning cores of massive stars produces selenium, alongside a large r-process share.
▸ Reactivity
Conductivity changes dramatically in light (photoconductive)First photovoltaic material commercialized. Selenium's resistance plummets when light hits it — the basis of early photocopiers and exposure meters.
▸ Applications
- Photocopier and laser-printer drums (legacy)
- Anti-dandruff shampoo (SeS₂)
- Photovoltaic and photoelectric devices
- Glassmaking decolorizer
▸ Curiosity
For decades nearly every plain-paper copier ran on selenium's photoconductive shift — organic drums and amorphous silicon displaced it, a materials change, not a digital one.
▸ Related readings
a resonance drawn between readings — not a claim that they share an origin.