Arsenic — the 'king of poisons and the poison of kings'. For millennia it was used for murder: its compounds are colorless, tasteless, and slow-acting. The Borgia family poisoned their rivals with it. Napoleon may have died from arsenic in the wallpaper of his room on Saint Helena.
But today arsenic saves lives. Arsenic trioxide (As₂O₃) cures acute promyelocytic leukemia with over 80% efficacy — one of the most successful anti-cancer drugs. And gallium arsenide (GaAs) powers the fastest microchips and solar panels for space.
In Bangladesh, over 100 million people drink water with naturally high arsenic levels. The WHO calls this the largest mass poisoning in history. Arsenic leaches from underground rock and enters wells.
But in electronics, arsenic is indispensable. GaAs transistors have 6 times higher electron mobility than silicon. That's why every smartphone contains GaAs chips for amplifying mobile signals. And silicon doped with arsenic becomes an n-type semiconductor.
Arsenic and its compounds are extremely toxic carcinogens (IARC Group 1). Lethal dose for humans — 100–200 mg. Arsine (AsH₃) is one of the most poisonous gases. Chronic exposure causes skin, lung, and bladder cancer. Workplace air limit — 0.01 mg/m³. Fume hoods, respirators, and protective suits required.
Arsenic is the 'poison of kings'. The Borgias, Medicis, and other noble families used it to eliminate rivals. Its compounds are colorless and tasteless.
Arsenic trioxide (As₂O₃) cures acute promyelocytic leukemia with >80% efficacy. The poison became a medicine — FDA-approved.
Medieval alchemists considered arsenic an intermediate substance between metals and non-metals. Modern science confirmed it — it's a metalloid.
Gallium arsenide (GaAs) powers the fastest microchips. Electron mobility is 6 times higher than silicon. It's in every smartphone.
Over 100 million people in Bangladesh drink arsenic-laced water. The WHO calls it the largest mass poisoning in human history.
| Isotope | Mass (u) | Abundance | Half-life | Decay |
|---|---|---|---|---|
75As | 74.921597 | 100.00% | stable | — |
Heating arsenic sulfide with soap