A Visual Encyclopedia of the Periodic Table

190

Noble Gases

Uses

Helium

He

2

Helium is the second lightest element

after hydrogen. This transparent gas was first

discovered in 1868 by Sir William Ramsay, a

Scottish chemist. Today, we know that a quarter

of all the atoms in the Universe are helium. It

is one of the main gases in the atmospheres of

giant gas planets, such as Saturn. Being so

light, however, helium is very rare on Earth: it

escapes from our atmosphere into space. It was

not until 1895 that chemists managed to collect

a sample of helium gas coming from uraninite, a

radioactive uranium mineral. Today, helium is

A particle accelerator is a

machine that smashes atoms together:

this one uses liquid helium to cool its parts.

Large Hadron Collider,

CERN, Switzerland

2 2 2

State: Gas

Discovery: 1895

Sat

urn

Natural gas

often contains

some helium.

a (^) g
la
ss
(^) s
ph
er
e
Pu
re
(^) h
el
iu
m
(^) in
Saturn's atmosphere
is made up of clouds of
hydrogen and helium.
Gas flare rig
Forms
This sample of
helium is trapped
in a glass sphere.
Helium is a
transparent gas,
but it glows purple
when electrified.
MR
I^ sc
anner
He
lium

• cooled

190-191_Helium.indd 190 12/12/16 5:40 pm