A neutron is a fundamental particle in the nucleus of an atom. Protons and neutrons have nearly the same mass and can exist as free particles away from the nucleus. Neutrons constitute more than half of all visible matter in the universe. They possess properties that make them ideal for various types of research. Their unique sensitivity to hydrogen, for example, allows them to locate precisely the atoms of hydrogen. Their sensitivity to hydrogen ensures the accurate determination of molecular structure when designing new curative drugs. When scattered from hydrogen in water, neutrons can locate the moisture in the wings of fighter jets. As a result, they can determine early corrosion and microscopic cracking in the wings that require replacement.
Scientists began to solve the mysteries of the atom at the start of the 20th century. They discovered that atoms consisted of tiny subatomic particles. An atom has a massive and positively charged nucleus that contains protons. Negatively charged electrons surround the nucleus. The number of the positively charged particles in the nucleus of an atom identifies a chemical element. Scientists were, however, unable to explain the occurrence of isotopes, or the occurrence of elements with the same atomic number but different atomic masses. In order to account for the phenomena, Ernest Rutherford proposed the existence of a subatomic particle neutron, which shared the same mass with the proton, but had no electric charge (Physics LAB). Rutherford suggested that the number of neutrons varied among the isotopes but the number of protons determine the element. There was, however, no way of proving the existence of neutrons. Through experiments, James Chadwick later proved the existence of the neutron.
Chadwick found the uncharged subatomic particle as he was experimenting on the irradiation of beryllium with the alpha particles. The irradiation emitted an unknown radiation that had no electrical charge, but was highly penetrating. While relying on previous studies, Chadwick placed other elements in front of the radiation and observed that the radiation freed the protons from the elements (Bowersox). By measuring the velocities of the protons, Chadwick noted that the unknown radiation was more massive than gamma radiation. Through experimental calculations, Chadwick concluded that the mysterious radiation was a subatomic particle that had no charge, but possessed a mass of nearly one atomic unit. His experiment, therefore, demonstrated the existence of neutrons. In 1935, Chadwick obtained the Nobel Prize in Physics for his discovery.
The neutrons in an atom allow scientists to solve many fundamental problems in chemistry and nuclear physics. Neutrons, for example, are important within the nucleus of an atom because they bind with the protons. Protons cannot bind directly to each other due to their strong electromagnetic repulsion. The neutrons, therefore, hold the atom’s nucleus together. Following the discovery, scientists began using the neutrons to set off nuclear reorganization in heavier atoms. The method allowed scientists to transform one element into another, through nuclear reactions. Research on the neutrons progressed and resulted in the development of nuclear energy. The researchers found that splitting the nucleus of the element uranium could release a massive amount of energy. Presently, nuclear physicists slam neutrons against each other in high-energy accelerators in order to study the microstructures of the nucleus.
Since the discovery of the neutrons, scientists have found numerous uses for the subatomic particles. An examination of the structures of different materials and the treatment of tumors utilize neutrons. The analysis of the water content in soil samples also uses the particles. Other uses include the production of nuclear power for the running of industries. The neutron discovery became a significant stage in the study of the strong and weak interactions among the subatomic particles. Neutrons play an important role in the life cycles of stars, particularly, the neutron stars. After the discovery, Chadwick assisted the US government in the development of nuclear weapons and witnessed the massive effects of a nuclear bomb at the Trinity test site. The advancement in nuclear physics that began in Chadwick’s time has continued to bear fruit to the present day.
Bowersox, Paul. “Sir James Chadwick’s Discovery of Neutrons.” ANS Nuclear Café. 19 Oct. 2011. Web. 29 May 2014.
Physics LAB. “Famous Experiments: The Discovery of the Neutron.” n.d. Web. 29 May 2014.