The Physics Of The Atomic Theory

Atoms of the same element can have different masses, this is called isotopes. After 200 years John Dalton discovery of the Dalton’s Atomic theory it is still used today John Dalton’s atomic theory is the foundation of which Chemistry was built on.

Around 2,500 years ago, Democritus and his partner Leucippus were the first ones to develop the atomic theory in written history. Their theory proposed that every kind of matter was made up of tiny particles, which were named atomos, which means that it is indivisible. This meant that Democritus and Leucippus thought there were little particles of everything, but, the next breakthrough in atomic theory wasn’t made until the early 1800s with a french chemist by the name of Antoine Lavoisier, he was the one who came up with the idea of the law of the conservation of mass, which states that matter stays the same even when it changes shape or form. Then, James Dalton said that all matter was made up of atoms, which were indivisible, and unbreakable.

The second main contributor toward the atomic structure was John Dalton. John Dalton was the one who brought the atomic theory talk back into play after 2000 years from Democritus. Dalton become fond of the atomic structure following his love from meteorology. He claimed that the forces of repulsion that caused pressure only were between the same atoms and the atoms inside a mixture had different weights and complexity. He then decided to calculate the atomic weights by determining the percentages of each composition in a compound. This allowed him to be able to

Democritus made the atomic theory widely known, which stated that the universe is composed of two elements: the atoms and the void in which these atoms exist and move. (More, 1646)

Around 1803 John Dalton, an English chemist developed the first useful atomic theory of matter. Amedeo Avogadro, the Italian chemist in 1811 published an article drawing the distinction between the atom and the molecule, which now is known as “Avogadro’s

Over the course of the last 5000 years, mankind’s knowledge has been constantly advancing. Chemistry, a branch of science, has experienced a tremendous leap and expansions since ancient Greek civilization. One of the major breakthroughs in the advancement in Chemistry was the creation of the Atomic theory, which laid a foundation for the modern-day Chemistry and future of science. The Atomic theory introduced the idea of atoms, which are defined as the discrete units of matter. There are five key scientists that significantly contributed to the Atomic model over a span of thousands of years. They are: Democritus, John Dalton, J.J. Thompson, Ernest Rutherford, and Niels Bohr.

There are many different experiments which can give varying intelligence about the makeup of matter, in different ways and with different conclusions. In this instance I will be looking at the discovery of the electron, how our understanding of it has changed over the years, and measure how it has contributed to where we are today.

One of Bohr’s most renowned accomplishments was his contribution to the atom. He discovered that the atom was a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus. Most physicists run experiments in order to come

Atomic Theories 1. John Dalton John Dalton based his theory on Democritus’ findings. This was that matter could be divided and split into several smaller “units”, eventually forming a tiny particle that couldn’t be divided. This particle is an atom. Democritus and other Ancient Greeks could not support their theory or findings due to the lack of technology, equipment and understanding of atoms.

In 1808, John Dalton published his theory that all materials were made up of atoms and that atoms can bond together in different combinations. After experimenting with his theory and proving it was indeed true alchemist, chemist and scientist were all on the hunt to find new atoms and this started a scientific revolution. With the inventions of better technology and the scientific innovation scientists were able to find many different atoms. Afterward chemist worked harder to determine whether these substance were elements. These scientist soon identified many groups to elements. A Russian chemist, Dimitri Mendeleev organized and formed the periodic table based on all of the information he had collected. Although Mendeleev did not have all

Thomson4 discovered the electron3 using a cathode ray4. In a cathode ray an electric current is passed through a discharge tube5 which causes a glowing light that, Thomson concluded, was made up of smaller particles. He then discovered that these particles had a negative charge and were actually electrons. Thomson knew that electrons had a negative charge and believed that matter must have a positive charge as well. From the knowledge he accumulated, he formed a model of what he believed the structure of the atom looked like. This model has come to be known as the Plum Pudding Model4. In 19004 a professor of theoretical physics, Max Planck4, discovered that when you vibrate atoms strong enough you can measure the energy. Planck called these packets of energy quanta. At the time, physicists believed that light consisted of waves. Albert Einstein4 concluded that the quanta behaved like discrete particles. For many years there was a controversy on whether light consisted of waves or particles. In 1911 Ernest Rutherford4 bombarded atoms with alpha rays. Rutherford used Radium as the alpha particles4 and shined them onto gold foil. This was called the Gold Foil Experiment4. The conclusion from this experiment was that positively charged matter scattered the alpha particles and that most of the space4 around these positively charged centers has nothing in it. Furthermore, Rutherford thought that electrons must exist somewhere within that empty space and that they orbited a positive center, like the planets orbit around the sun. Rutherford also speculated that atoms consisted of a compact positively charged nucleus4 as well as that most of the atom’s mass is contained in the nucleus. In 1919 Rutherford finally identified the particles of the nucleus as discrete positive charges of matter and named them protons4. He developed a model of the atom but, due to the theory of electricity and magnetism, it was predicted, according to this model,

In the science community, we have had many advancements made on the atomic atom. It began in 460 B.C. when a man named Democritus discovered that particles can continuously be broken down into smaller pieces. That idea is what started the evolution of what we know now as the modern atom, which has been clarified by Niels Bohr.

Although difficult to imagine, there existed a point in time where people lived in an environment where everything was visually there, but what it was made up of remained a thoughtless mystery. Today, this is why atomic theory is an important basis for the foundation of chemistry, physics, and various other scientific discoveries. Without atomic theory, the basic building blocks of the world would remain unclear, which would make understanding the study of science almost impossible. Atomic theory explains the idea that within the composition of matter, there exists numerous particles called atoms. This idea of the atom has been experimented and researched by numerous scientists whom built upon each others discoveries-one scientist being J.J Thomson.

The Discovery of the Atom first came from the Greeks which made a theory “The idea that all matter is made up of tiny, indivisible particles, or atoms, is believed to have originated with the Greek philosopher Leucippus of Miletus and his student Democritus of Abdera in the 5th century B.C. (The word atom comes from the Greek word atomos, which means “indivisible.”)” (InfoPlease Atomic theory)

I am going to discuss the modern concept of the atom. I am going to give a brief history of the atomic model including Thomson's atom, Rutherford's atom, Bohr's atom, and Schrödinger's atom. I am going to include a diagram for each of these models.