astatine
Rarest natural element
Astatine is a radioactive chemical element, atomic number 85, the rarest naturally occurring element on Earth.
It belongs to the halogen group alongside fluorine, chlorine, bromine, and iodine, but is so unstable that its properties are difficult to study—most isotopes decay within seconds.
Scientists have never assembled enough astatine to see what it looks like.
Spiral-path particle accelerator
- particle acceleratorDevice speeding subatomic bits
- bombardmentSustained projectile assault
- nuclear reactionAtoms changing their cores
- transmutationComplete change of form
Gradual organic breakdown
- half-lifePeriod for fifty-percent reduction
- alpha particleIonizing emission from decay
- beta particleEmitted electron or positron
- gamma rayHigh-energy nuclear emission
isotopes · radiation · nuclear · ionizing · radionuclide · radioisotope · dosimeter · radioactive decay
In short supply
- fleetingPassing very quickly
- ephemeralLasting very briefly
- transientTemporary, soon departing
- short-livedLasting only briefly
Pale yellow halogen gas
- chlorineHalogen disinfectant element
- bromineElement thirty-five, liquid halogen
- iodineAntiseptic element, atomic fifty-three
- halideHalogen-element compound
diatomic · electronegativity · nonmetal · reactivity · anion · oxidizing agent
Systematic display of elements
- metalloidElement straddling two classes
- protonsPositive nuclear particles
- neutronsUncharged subatomic particles
- electronsNegative charges in atoms
atomic mass · nucleus · subatomic particles · chemical bonds · orbital · ionization · quantum mechanics · crystal structure
Medical radiation for cancer
- cancer treatmentMedical intervention for malignancy
- thyroidHormone-producing neck gland
- radiopharmaceuticalMedicinal radioactive substance
- oncologyCancer medicine specialty
cyclotron
Spiral-path particle accelerator
- particle acceleratorDevice speeding subatomic bits
- bombardmentSustained projectile assault
- nuclear reactionAtoms changing their cores
decay
Gradual organic breakdown
- half-lifePeriod for fifty-percent reduction
- alpha particleIonizing emission from decay
- beta particleEmitted electron or positron
gamma ray · isotopes · radiation · nuclear · ionizing · radionuclide · radioisotope · dosimeter · radioactive decay · transmutation
scarce
In short supply
fluorine
Pale yellow halogen gas
- chlorineHalogen disinfectant element
- bromineElement thirty-five, liquid halogen
- iodineAntiseptic element, atomic fifty-three
halide · diatomic · electronegativity · nonmetal · reactivity · anion · oxidizing agent
periodic table
Systematic display of elements
- metalloidElement straddling two classes
- protonsPositive nuclear particles
- neutronsUncharged subatomic particles
electrons · atomic mass · nucleus · subatomic particles · chemical bonds · orbital · ionization · quantum mechanics · crystal structure · superheavy
radiotherapy
Medical radiation for cancer
- cancer treatmentMedical intervention for malignancy
- thyroidHormone-producing neck gland
- radiopharmaceuticalMedicinal radioactive substance