Atomic Age: ATOMIC CHAIN REACTION

When a piece of paper is lighted with a match, the paper particles first heated set others on fire; these in turn ignite others, and so on. The same sort of chain reaction must be started for a successful large-scale atomic explosion. Above, the rare form of uranium, U-235, is shown breaking down into barium and krypton (only one of several possible disintegrations). The "match" is a neutron source at left. (Radium mixed with beryllium is a common source of neutrons.)

The uranium nucleus splits into barium and krypton atoms, which are highly excited, unstable and artificially radioactive. They throw off gamma...

Want the full story?

Subscribe Now

Subscribe
Subscribe

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!