Tag Archive | James Chadwick

The History of the Atom

images (36)Take a look around you and see where you are. What is the closest object to your right or your left? What are the things surrounding you and ask yourself, what are they made up of? They are all made up of atoms. An atom is the basic building block for matter. Everything in this world contains atoms as they have all matter.

The study of atoms has not been studied for a long period of time. The first person to suggest the idea of the atom was Greek philosopher Democritus. He thought to himself what would happen if you kept on breaking matter into smaller and smaller pieces. He knew you would have to reach the smallest point available and he would call these tiny particles atoms. However, his idea was ultimately rejected by everyone including Aristotle. Democritus’ idea was rejected on the grounds that is was too silly and due to the fact that since Aristotle’s opinion was highly valued many people would believe whatever Aristotle would say. This idea was never fully studied again until in the early 1800’s by a scientist called John Dalton.

His atomic theory was the first time the idea of the atom was placed on a solid foothold. In short, his theory stated that elements consisted of tiny particles called atoms. Although, not all of his points were true his theory still helped pave the way for future investigations into this topic.

In 1897, J.J. Thomson discovered electrons. He was able to discover it using a cathode ray tube. In his experiment he sealed gases in a glass tube fitted with electrodes.The electrodes were connected to a source of electricity, and when turned on one would become negatively charged while the other turned positively charged. This resulted in a bright beam called a cathode ray. J.J. Thomson put positively and negatively charged magnets on opposite sides of the glass. The cathode ray would be attracted by the positively charged magnet while being deflected by the negatively charged magnet. He hypothesized that the cathode ray was made up of tiny negatively charged particles called electrons.

However, the biggest contribution to the research of the atom came from Ernest Rutherford. He discovered the nucleus, the center of the atom. He performed a gold-foil experiment where he shot alpha particles at a thin gold foil. Much to his surprise, a small portion of the alpha particles bounced off at very large while almost all passed through the foil with ease. Thanks to his experiment he hypothesized that a small region in the center of the atom was positively charged and called this the nucleus.

In 1930, James Chadwick began hitting beryllium with alpha particles and when it hit beryllium it began emitting radiation. Chadwick studied this radiation and found neutral particles that weighed slightly more than the mass of protons. He called these neutral particles, neutrons.

Today, we know a lot more about the atom compared to one thousand years ago. We know it is the fundamental building block for all life. Thanks to the many contributions of scientist over the years we can continue their work and gather more data on this small but enormous part of our life. We have proved that atoms can be split and we have used this to benefit our lives and we continue to research more ways on how atoms can better our lives. We can use nanotechnology, which uses nano atoms, to detect and possibly even exterminate cancers and tumors in our bodies.