radium

Everyday

A rare, radioactive metal element (symbol Ra) that gives off dangerous radiation and glows faintly in the dark. tree →

In the lessons

In science lessons radium is linked with Marie and Pierre Curie, who discovered it, and with learning about radioactivity. In history lessons it is a warning story: people once put radium in watch paint, toothpaste and drinks, not knowing it was harmful; the "Radium Girls" who painted glowing watch faces became very ill. It tells the reader about danger hidden in something that looks magical.

Examples

• Marie Curie discovered radium with her husband Pierre. tree →
• Radium glows with a faint blue-green light. tree →
• Radium is radioactive, so it is very dangerous to touch. tree →
• Old watches had radium paint so you could read them in the dark. tree →
• The Radium Girls got ill from licking their paintbrushes. tree →
• Radium's symbol in the periodic table is Ra. tree →

Note

Uncountable: "radium is", not "a radium". Chemical symbol Ra, atomic number 88. Myth from long ago: radium was sold as healthy; it is not. Do not confuse with "radius" (a line from the centre of a circle).