Journey Inside the Atom
By Mohammad Asad Raza · Blogger / Writer
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Journey Inside the Atom An atom is a very tiny particle that makes up everything around us. We cannot see an atom with our naked eyes because it is extremely small. But scientists have discovered that an atom is not a simple solid ball. It has smaller particles inside it. The journey inside the atom helps us understand its structure and the particles present in it. Long ago, scientists thought that matter could not be divided into smaller parts. Later, they discovered that matter is made up of atoms. John Dalton gave the first modern atomic theory. According to him, atoms are very small particles and atoms of the same element have similar properties. Later, scientists discovered that atoms contain smaller particles called electrons, protons and neutrons. Discovery of Electron The electron was discovered by J.J. Thomson. He used a discharge tube and studied cathode rays. He found that these rays were made up of very small negatively charged particles. These particles were called electrons. The electron is much smaller than an atom. It has a negative charge. Thomson proposed a model of the atom called the plum-pudding model. According to this model, an atom was considered a positively charged sphere with negatively charged electrons spread inside it. However, this model could not explain all the observations made by scientists. Rutherford's Experiment In 1911, Ernest Rutherford performed an important experiment. He used a very thin gold foil and bombarded it with alpha particles. Most of the alpha particles passed straight through the gold foil. Some particles were slightly deflected, and a very small number bounced back. This result was surprising. Rutherford concluded that most of the atom is empty space. He also concluded that almost all the positive charge and mass of an atom are concentrated in a very small central part called the nucleus. The electrons move around the nucleus. The nucleus is extremely small compared with the size of the atom, but it contains mon