
150
MELTING POINT
BOILING POINT
DENSITY
Thallium is known for being almost as toxic
as arsenic. A single gram is enough to kill an
adult. It was the British serial killer Graham
Young’s murder weapon of choice and also
appeared in Agatha Christie’s The Pale Horse.
It was also widely used as a rat and ant poi-
son until the 1970s, when this use was pro-
hibited for obvious reasons. More helpfully,
it is used as a radioactive isotope to help us
find irregular blood flows and the like.
WITH THE UNEXPECTED
ABILITY TO DETECT
HEART ATTACKS
DISCOVERY YEAR: 1861
The boron family
Specialist
uses
Solid
Soft metal
The most
toxic of all
the heavy
metals
Used in nuclear ...