| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| A free radical is an atom or molecule that has an unpaired one of these | an electron | $1,200 | DJ | CHEMISTRY | 2008-05-30 | #5475 | |
| An atom that loses one of these becomes a cation, a positively charged ion | an electron | $600 | DJ | CHEMISTRY | 1993-02-05 | #1945 |