EMFs are divided into two main categories based on whether or not the radiation level is high enough to ionize atoms. To ionize means to literally move electrons around. An electron is a sub-atomic particle that is the primary carrier of electricity in solid objects. When an atom is exposed to ionic radiation, it can lose its electrons or receive new ones. Based on how many electrons an atom has, it can have an enormous impact on chemical and physical properties.
For example, sodium chlorite (table salt) will safely dissolve when put into water. By contrast, if pure sodium (a metal) is put into water, it bursts into flames. This is because there is a chemical reaction happening on a subatomic level. An electron is being taken from the sodium atoms and given to the hydrogen atoms in the water. The hydrogen with the new electron is now lighter and changes from a liquid to a gas and begins to rise into the air. When the hydrogen gas touches the oxygen in the air – BOOM! This is a natural ionic reaction.
When humans purposefully manipulate matter on an atomic level, it can have enormous impact. What makes atomic bombs so different from a conventional bomb is not just their blast radius, but also that the explosion releases large amounts of radioactive elements and ionizing radiation into everything in the surrounding area. Too much radiation can cause cancer. Yet, targeted radiation (chemotherapy) can also cure cancer. Manipulating atomic energies is a strange new discovery and we are still learning how to use it properly.