The electrons are usually thought of as orbiting the tiny nucleus, like planets orbiting the Sun. As you would expect, properties of an atom give rise to some of the most important properties of an element. This is a question that a nuclear scientist is best able to answer, because the answer lies in the core, or nucleus, of atoms. In this line carbon, for example, is transformed into oxygen. Together the elements created by fusion make the stuff of life.
Nuclear reactions are the most fundamental of all reactions, creating the elements themselves.
They are going on today, just as they have been happening since the Big Bang. Most nuclear activity occurs in the stars, although a small amount is happening in the rocks of the Earth. Changing one element into another The change from one element to another is called transmutation. Remember that atoms are made up of different combinations of protons, neutrons and electrons, so the break up of a neutron leaves behind an atom with a different combination of neutrons, protons and electrons. This new combination is a new element.