the.com/isotopes
same element, different weight class — chemistry's identical twins with different shoe sizes.
means atoms of the same element that share a proton count but differ in neutrons, giving them the same chemistry but different mass.
from coined in 1913 by margaret todd, suggested to chemist frederick soddy, from greek isos (same) plus topos (place) — because they occupy the same slot on the periodic table.
same slotdifferent masses share one periodic table position
carbon datingcarbon-14 decays at a known, clock-like rate
hydrogen has threeprotium, deuterium, tritium, wildly different weights
unstable onesradioactive isotopes decay, releasing detectable energy
for instance
carbon-14 — used to date fossils and artifacts up to 50,000 years old
uranium-235 — fuels nuclear reactors and the hiroshima bomb, 1945
iodine-131 — treats thyroid cancer, half-life just 8 days
deuterium — heavy hydrogen, key ingredient in fusion reactor research