What Causes Radioactive Materials and How Are Atoms Affected?

[Bluepie97]

Homework Statement

Marie curie referred to radioactivity as an invisible radiation that exposed photographic plates. What causes materials to be radioactive and what part of the atom is affected.

Homework Equations

none

The Attempt at a Solution

cosmic rays and fallout? The electrons are removed from the atom called ionized. Also uranium causes radioactive materials.

 

[jedishrfu]

Try reading up on the definition of radioactive decay and you'll find better answers to your questions.