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91 Pa
Element Revision Sheet

Protactinium (Pa)

Actinoids Block F Group Actinides • Period 7
Superhero Identity

"Meet Protactinium, the Ghostly Catalyst! This ultra-rare powerhouse is the shadowy mastermind behind atomic transformations, existing for mere moments but shaping the fate of much heavier elements."

A memorable persona to anchor Pa in your mind.

Density

15.37

Grams per cm³

Melting Point

1572

Celsius (°C)

Atomic Radius

243

Radius (pm)

Everyday Connection

Daily Life Link

Think of it as the fleeting spark that ignites a complex chain reaction, much like the first domino in a super-long line.

Discovery & History

Year Discovered

1913

Discovered By

Kasimir Fajans & Oswald Helmuth Göhring

Origin of Name

"The name is derived from the Greek 'protos', meaning first, as a prefix to the element actinium, which is produced through the radioactive decay of proactinium."

Technical Properties

Atomic Mass

231.036 u

Standard State

solid

Boiling Point

4000°C

Electron Configuration

[Rn] 5f26d17s2

1st Ionization Energy

5.89 eV

Electron Affinity

N/A

Oxidation States

[+5 +4]
Appearance

"Imagine a shimmer of silver, quickly fading to a dull grey as it battles the air."

Did You Know?

1

Its name, 'Protactinium,' literally means 'first actinium' – because it's the radioactive parent that decays directly into actinium. Talk about a glow-up origin story!

2

Protactinium holds the title for one of the rarest naturally occurring elements on Earth. Finding it is harder than spotting a unicorn at a rock concert!

3

Every single known isotope of Protactinium is radioactive. This element doesn't do 'stable' – it's all about that high-energy transformation life!

4

Scientists consider Protactinium highly toxic and fiercely radioactive, making it one of the most dangerous elements to handle. Safety first, *always*!

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