In 1902 Ernest Rutherford and Frederick Soddy discovered that radioactive elements, such as uranium and thorium, broke down into other elements in a predictable sequence or series. This amazing fact seemed like alchemy to many, but American chemist Bertram Borden Boltwood (1870-1927) was intrigued.In 1902 Ernest Rutherford

Why is it called half-life?

The name Half-Life was chosen because it was evocative of the theme, not clichéd, and had a corresponding visual symbol: the Greek letter λ (lower-case lambda), which represents the decay constant in the half-life equation.