what is reactivity
What Is Chemical Reactivity? Did you know that the periodic table was built in such a way that it would help people point out elements known to be reactive? Now, who said chemists aren't creative? Before we dive into this neat fact, let me explain what chemical reactivity means. By definition, chemical reactivity occurs when substances change chemically. What is most often produced from this type of change is something in the form of energy, such as heat and combustion. A simple way of thinking about reactivity is to imagine mixing two or more things together and watching what happens when they hang out or mingle with each other.