| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| These electromagnetic rays were once called Roentgen rays | X-rays | $200 | DJ | PHYSICS | 1991-10-09 | #1633 | |
| Paper can stop alpha particles, a thin piece of aluminum, beta particles, & a sheet of lead, these rays | X-rays (gamma rays) | $200 | J | NUCLEAR PHYSICS | 1991-04-22 | #1541 |