Other forms: half-lives
A half-life is the time it takes half a radioactive sample to decay. Measure the half-life.
It never changes, so after two of them a quarter is left and never nothing. Half-life ranges from fractions of a second to billions of years depending on the element.
1nounhalf-lifeThe time it takes half a radioactive sample to decay.
“The half-life was twenty-four thousand years.”
half-life is a period.
Middle English
half
English
half
English, today
half-life
From half- + life. half comes from Middle English half. From Middle English half, halfe from Old English healf (“half”); as a noun, 'half', 'side', 'part', from Proto-West Germanic halb, from Proto-Germanic halbaz. 2
Etymology from Wiktionary, CC BY-SA