Nuclear warhead

A nuclear warhead is a powerful Earth weapon which derives its destructive power from nuclear reactions. With a naquadah enhancement, a small nuclear warhead becomes powerful enough to, apparently, destroy the entire Earth.

Jack O'Neill attempted to destroy the Abydos Stargate with a nuclear warhead, but Ra took the weapon and prepared to send it back through the gate to Earth. However, O'Neill and Daniel Jackson used a ring transporter to send the bomb aboard Ra's ship. (Stargate)

When George Hammond discovered the Abydos Stargate was still standing, he planned to send another, more powerful, bomb through, but Jack O'Neill persuaded him otherwise. (SG1: "Children of the Gods")