A cobalt bomb is a type of "salted bomb": a nuclear weapon designed to produce enhanced amounts of radioactive fallout, intended to contaminate a large area with radioactive material. The concept of a cobalt bomb was originally described in a radio program by physicist Leó Szilárd on February 26, 1950.
In contrast, the first test of a thermonuclear weapon, or hydrogen bomb, in the United States in November 1952 yielded an explosion on the order of 10,000 kilotons of TNT. Thermonuclear bombs start with the same fission reaction that powers atomic bombs — but the majority of the uranium or plutonium in atomic bombs actually goes unused.
Napalm was used in flamethrowers, bombs and tanks in World War II. It is believed to have been formulated to burn at a specific rate and to adhere to surfaces to increase its stopping power. During combustion, napalm rapidly deoxygenates the available air and generates large amounts of carbon monoxide and carbon dioxide.