Really wishing I had paid more attention in high school. I assumed that reactive meant that the element either needed to gain or lose electrons causing it to "want" to grab onto another or be grabbed. Sodium being an example. If I am correct with that part, this next part is where I am picking up some confusion. Once it is straightened out I will probably have a good number of other questions to ask. What are the differences with reactive, and unstable? And where does radioactive come into play among them, if at all? I will wait for an answer before I throw more into this thread. I am sorry if this happens to be a very simple question and annoys anyone. I have grown to not fully trust many sources and prefer talking with a human about the questions over using a restrictive search engine.