Nuclear Chemistry: Introduction

Nuclear Chemistry

Traditional chemical reactions occur as a result of the interaction between valence electrons around an atom's nucleus. In 1985, German physicist Wilhelm Roentgen discovered that highly energetic rays could penetrate matter. He called these X-rays. In 1896, Antoine-Henri Becquerel expanded the field of chemistry to include nuclear changes when he discovered that uranium emitted radiation. Soon after Becquerel's discovery, Marie Sklodowska Curie began studying radioactivity and completed much of the pioneering work on nuclear changes. Any material such as uranium that spontaneously emits gamma radiation is said to be radioactive. Curie found that radiation was proportional to the amount of radioactive element present, and she proposed that radiation was a property of atoms (as opposed to a chemical property of a compound).

Additional radioactive elements were later discovered by the Curies, Rutherford and Frederick Soddy. They also found out the chemical properties of a radioactive element change as it undergoes radioactive decay.

The nuclear reactions have become tremendous source of energy all over the world, both for peaceful and destructive purposes. Nuclear chemistry is the branch of chemistry, which deals with the study of atomic nucleus and nuclear changes.

The isotopes of elements up to atomic number 19 have mostly stable nuclei. Elements with atomics numbers 20 to 83 consists of mixture of isotopes, some of which have unstable nuclei. When the isotope is unstable, it is radioactive, which means that it spontaneously emits energy in the form of radiation period. Radioactive isotopes are called radioisotopes. They emit radiation during the process of radioactive decay.

     The nuclei of all isotopes with atomic number greater than 83 are unstable and undergo spontaneous decay. When a change in the nucleus of an atom results in the transformation of the atom from one element to another, the change is called transmutation.