Many different scientists contributed to the atomic theory known today. Every single one of them played an important role in creating the atomic theory known today. Around 400 BCE Leucippus, the scientist who originally came up with the atomic theory, began to lay a foundation for the theory known today. Then, Democritus adopted the ideas of Leucippus , his mentor. Democritus soon developed the idea of an atom. Democritus believed everything was made up tiny particles of matter, he called these particles atoms. He chose this name because, in Greek, atom means indivisible. After Democritus, Isaac Newton was the next scientist to contribute to the atomic theory. Isaac Newton began to realize that atoms were constantly moving and were not …show more content…
This idea came from the findings of Democritus. His second conclusion was that all atoms of one type have the same mass and properties. Along with this point, Dalton understood atoms of different types had different masses and properties. Dalton’s fourth point consisted of the fact that chemical reactions do not create, change, or destroy elements, they are only rearranged in these reactions. The final point of Dalton’s theory was when different elements combine, they do so in some ratio of whole numbers. John Dalton was able to find mass numbers for twenty one different elements. The Law of Mass Conservation, created by Antoine Lavoisier, was supporting evidence to Dalton’s atomic theory. Next, J. J. Thompson contributed ideas to the existing theory. In 1898 he used a cathode ray and discharge tube to aid in the discovery of electrons. The electron has an antimatter counterpart. This counterpart is known as the positron, positrons have the same mass as electrons. J.J. Thompson was able to determine the existence of a + particle . He also founded the plum pudding model , this model showed negative particles scattered around a positive …show more content…
His work helped to contribute to the modern understanding of the atomic theory. Thus, at the points A B C and D the electron would be subjected to maximum repulsive and attractive forces while the positions a b and c would be stable But once disturbed from one of the latter positions the electron would oscillate for a while and finally shift over into a new position of equilibrium At the distance OE the curve representing the force exerted on the electron would become practically the same as that corresponding to Coulomb's law Such a law of force might thus explain radiation phenomena and perhaps the raison d etre of the constant h in the quantum theory. In 1905 Albert Einstein was the next scientist to contribute to the atomic theory findings. His work on the theory of relativity became the basis of nuclear energy. In 1909 came the following important discovery, the discovery of the nucleus. Ernest Rutherford started to form an idea of the structure of an atom. Rutherford used the scattering of alpha particles when shot through gold foil to discover the structure of an atom, he called this experiment the gold foil experiment. Rutherford also decided to call Thompson’s + particles protons. P+ is another symbol that means
The Scientific Revolution brought a new way of thinking about the universe, and brought an end to Europe’s medieval past. Many scientists have devoted their lives to creating new ideas about the physical universe. These scientists created the assumption that the universe and nature are governed by mathematical laws. Each of the three scientists, Nicolaus Copernicus, Johannes Kepler, and Isaac Newton contributed to the breakdown of the medieval world view. Nicolaus Copernicus thought past the idea of a geocentric universe, and established the idea of a heliocentric theory, or a sun-centered universe. Johannes Kepler presented the idea of an ellipse, otherwise known as the planets following an oval shaped orbit, and not a perfect circle. Finally,
John Dalton wrote the modern atomic theory, a fundamental component of that is, the mole ratios of elements in a compound will be small whole numbers.
One of J.J. Thomson's most significant contributions to science, and thus to the study of atomic theory, was his discovery of the electron. Before the discovery of the electron, the atom was already associated with having electric charges-both positive and negative-but the idea of an electron existing as its own particle was unheard of. It was in 1897 when Thomson first conducted the beginning of his now famous experiment, in which he used a cathode ray tube to aid in his findings. A cathode ray tube, is a vacuum tube in which cathode rays, negatively charged particles, are produced at the cathode and travel through the vacuum, which is created when gas is extracted from the tube. J.J. Thomson discovered that in order to determine
-Henry Gwyn Jeffreys Moseley- Worked with Ernest Rutherford, experimented with 38 metals, he found that the positive charge of each element’s nucleus increased by one from element to element as they were arranged in Mendeleev’s periodic table, lead to modern definition of atomic number (# of protons in atom’s nucleus) and the recognition the
Then in 1661, Irish chemist Robert Boyle supported the philosophers’ theory of how chemical elements are made up of the simplest matter, backing the theory of how matter makes up all life and is the smallest living thing (Doc. 1). But a bombshell happened in 1803 when John Dalton backed up all three theories by discovering that atoms make up all matter, and chemical compounds are made of atoms (OI).
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.
Before Rutherford’s Geiger-Marsden experiment the most popular model of the atom was the “plum pudding model” developed in 1904 by the person who also discovered the electron in 1897, J.J. Thompson. It was the most common model of the atom and stated that electrons (plum) floated around with
Leucippus and Democritus discovered the atom(doc. 1). Ernest Rutherford split the atom and discovered that the atom is made of smaller particles and that atoms have a positively charged nucleus and largely empty space(doc. 1). Without Leucippus and Democritus, no one could expand on the idea of the atom and without Rutherford no one would have thought of the nucleus and what is inside the atom(doc. 1). Atoms are so small
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)
Dalton was the son of a Quaker weaver. When only 12 he took charge of