The rule is that a sample is safe when its radioactivity has dropped below detection limits. And that occurs at 10 half-lives. So, if radioactive iodine-131 (which has a half-life of 8 days) is injected into the body to treat thyroid cancer, itâll be âgoneâ in 10 half-lives, or 80 days.
The term 'ratchet' has no less than two distinct meanings. As an adjective, it describes a person, usually a woman, or activity, who is out of hand, out of control, generally whack in some way, dirty, ghetto, unattractive, Crucian, or just generally disliked.
A racket is used to play tennis, badminton, or squash, and it can also be spelled racquet. Another definition of racket is an unpleasantly loud noise; if your neighbors were playing horrible, loud music, you could yell out the window, Stop that racket! Informally, the word racket also means illegal scheme, especially for making money. The French word requette means palm of the hand, and racquet originally referred to a tennis-like game played by hitting a ball with the hand.