| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| It's defined as the time required for 50% of the atoms of a radioactive substance to decay into another substance | half-life | $800 | DJ | NUCLEAR PHYSICS | 2003-02-14 | #4255 | |
| This measure is used for radioactive decay because the time for all atoms to break down is unknowable | half-life | $400 | DJ | PHYSICS | 1998-11-20 | #3270 | |
| Half the atoms in a radioactive substance decay in the time period called this | half-life | $600 | DJ | PHYSICS | 1985-04-19 | #160 |