why radium is dangerous
Radium is a highly radioactive alkali metal. It undergoes alpha decay, which is radioactive decay by the release of an alpha particle from a nucleus. The alpha particle is a helium-4 nucleus, and it can do a lot of damage. If an individual is up against a radium source, or if he ingests or breathes radium, he will have tissues exposed to the extremely destructive radiation. That's what makes radium so dangerous. That and the fact that its radioactive decay daughters are also radioactive, and an individual exposed to radium and having that radium decay (causing biological damage) will then face the radiation hazards of the daughters of radium, because they are all radioactive, too.