// MATTER · ELEMENT 90 / 118atoms.no/elements
Th90
Thorium
Th·Z 90·Actinide·232·⭕ 7B · F Major
▸ The reading
interpretive · artThorium's half-life is fourteen billion years — most of the thorium ever forged in neutron-star mergers is still exactly where it landed, older than the planet holding it. It lit a century of gas mantles and anchors alternative-reactor research. The most patient inventory on the table, seated at 7B.
The science below is cited as science; the symbolic layers are flagged as interactive art.
⚜ Periodic Frequency
7BF Major
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 — named for the Norse god Thor · Sweden · 1828
▸ Stellar origin
r-process (neutron-star mergers)²³²Th — the only naturally common thorium isotope — was forged in r-process events early in galactic history. Its 14-billion-year half-life means most original Th is still here.
▸ Reactivity
Self-passivates with a black oxide layer; fertile nuclear materialCaptures a neutron to become ²³³U, a fissile uranium isotope — the foundation of proposed thorium-fueled molten-salt reactors.
▸ Applications
- Gas-mantle lighting (historical)
- Thorium-fueled reactor research
- Aerospace alloys (Mg-Th)
- High-quality camera lens glass (legacy)
▸ Curiosity
Half-life of 14 billion years — most of the thorium that ever existed is still right where it was forged, in stellar mergers older than the Earth.
▸ Related readings
a resonance drawn between readings — not a claim that they share an origin.
Actinide seriesAcActiniumPaProtactinium
f-blockAcActiniumPaProtactinium
Adjacent ZAcActiniumPaProtactinium