A Visual Encyclopedia of the Periodic Table

112

Lanthanides

Neodymium

Nd

60

State: Solid

Discovery: 1885

State: Solid

Discovery: 1945

60

61

60

61

84

84

Promethium

Pm

61

Strong magnets made of neodymium can be

used to lift thousands of times their own mass.

This element was discovered in 1885 by the Austrian

chemist Carl Auer von Welsbach, and it was originally

used to colour glass. Small amounts of neodymium

turn glass pinkish purple. Today, this element is

also employed in lasers used in eye surgery.

Promethium is the rarest lanthanide element.

Any promethium that was in Earth’s rocks decayed

billions of years ago. Promethium is therefore

produced artificially in nuclear reactors. Being very

radioactive, it is used in some missiles, because

it converts this radioactivity into electrical power.

The addition of promethium also makes some

paints glow in the dark.

This paint glows as a result

of radioactive promethium.

The pure

element turns

black when it

reacts with air.

Promethium-rich paint in

a tin seen from above

Missile

This missile uses radioactive

promethium for electrical power.

This glass gets

its colour from

very tiny amounts

of neodymium.

P

in

k

(^) g
la
ss
Laborator y sample
of pure neodymium
112-113_Neodymium_Promethium_Samarium_Europium.indd 112 12/12/16 5:39 pm