Actinium (Ac)
"The Glimmering Dynamo, Actinium unleashes a dazzling burst of pure energy, glowing with fierce power before rapidly fading away, leaving a legacy of intense radiation in its wake."
A memorable persona to anchor Ac in your mind.
10.07
Grams per cm³
1050
Celsius (°C)
260
Radius (pm)
Daily Life Link
Imagine a natural, glowing battery that's incredibly powerful but also super dangerous and short-lived.
Discovery & History
Year Discovered
1899
Discovered By
André-Louis Debierne
Origin of Name
"The name is derived from the Greek ''actinos'', meaning a ray."
Technical Properties
Atomic Mass
[227] u
Standard State
solid
Boiling Point
3200°C
Electron Configuration
[Rn] 6d17s2
1st Ionization Energy
5.17 eV
Electron Affinity
N/A
Oxidation States
"A soft, silvery-white metal that famously glows with an ethereal blue light in the dark."
Did You Know?
Actinium gets its name from the Greek word 'aktis' or 'aktinos,' meaning 'ray' or 'beam,' a perfect nod to its incredibly intense radioactivity!
Forget glow sticks! Actinium compounds glow with a beautiful, eerie blue light in the dark, not from phosphorescence, but from its fierce radiation exciting the surrounding air.
This element is mind-bogglingly rare! You'd be hard-pressed to find it anywhere, as it exists only in tiny, trace amounts within uranium ores like pitchblende.
Actinium-227, its most stable isotope, has a blink-and-you-miss-it half-life of just 21.77 years – that's practically instant in geological time!