Atom and Atomic Theory (Essay Sample)

Atom and Atomic Theory Name of Student Institutional Affiliation Course Instructor Date Atom and Atomic Theory The discovery of the atom has significantly impacted the development of science, evoking further people's interest and significant contributions made by John Thompson, Ernest Rutherford, and Antoine Becquerel. In physics, atomic theory is a scientific model of the nature of matter, which declares that this very matter is composed of discrete units called atoms, for example, the smallest particles of matter. Ancient Greeks assumed the existence of atoms. The ancient Greek philosophers Leucippus and Democritus invented the word' atom'. Nevertheless, the idea that matter consists of discrete units originated in theological theories rather than experimentation (Pullman & Axel, 2011). The philosophers could not prove their theories in practice but left a great legacy for future generations. Atoms were thought to be the most minute possible division of matter until the nineteenth century, considered the peak of scientific discoveries. In 1897 John Thomson discovered the electron through his work on cathode rays. He found that atoms "contain the negatively charged electrons" (Pullman & Axel, 2011). The experiments of Ernest Rutherford showed that every atom has a nucleus, which is extremely small compared to the atom's size but contains almost its entire mass (Rutherford, 2012). Apart from that, Antoine Becquerel discovered that atoms of some elements could spontaneously lose particles, becoming atoms of different elements. This phenomenon is now known as radiation and is widely used in practice (Rutherford, 2012). As a result, ...