Democritus (460 BC- 370 BC) (Abdera, Greece)
- Democritus was a Greek Philosopher who was the first individual to utilize the term atom. He imagined that if you take a bit of matter and divide it and keep on dividing it, you will eventually come to a point where you could not isolate it any longer. This principle or fundamental unit was what Democritus called an atom.
He called this the theory of the universe:
• all matter compromises of atoms, which are bits of matter too little to be seen
• there is an unfilled space between atoms
• atoms are completely solid
• atoms have no internal structure
• each atom (of an alternate substance) is different in size, weight and shape
Fun Fact: Democritus was known as “The Laughing Philosopher.” He was named this way because he was often cheerful while working
Antoine Lavoisier (1743-1794) (Paris, France)
- Antoine Lavoisier was known as the “Father of Modern Chemistry.” He was the primary individual to produce a list of thirty-three elements in his textbook and he also devised the metric system. Antoine found/ recommended that burning happens when oxygen combines with different elements. He also found/ proposed the law of conservation of mass which states, in a chemical reaction, matter is neither created nor destroyed.
Fun Fact: One of the elements listed in his textbook was “light.”
John Dalton (1766-1844) (Cumberland, England)
- John Dalton was the first to adjust Democritus’ theory into the main present day atomic
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.
The Ancient Greeks were the firsts to speculate on the composition of matter. They thought that it was possible that individual particles made up matter.
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).
The field of science during the times of the Greeks have greatly influenced the modern world as one perceives it in the present day. The atomic theory has much responsibility for the relation of Greek thought and modern beliefs. Democritus was one of the fir4st Greek philosophers to explain the theory of the atom. He said that it was indivisible. Furthermore, he explained that each element is made of particles, and that change occurs by the transfer of the atoms. In comparison to the modern day atomic theory, Democritus had the correct notion as to the significance of the atom-it is indivisible. From the research done, Democritus’ idea of the atom did not directly influence the contemporary theory of the atom. The Greek
John Dalton was a British chemist born in 1766 in England to a Quaker family. His family was poor and he was homeschooled until at age 15. He and his brother ran a school. He had the biggest effect on the atom. He was the first to bring back the idea of an atom and prove it. One reason Dalton’s discovery is important is without it
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
A man by the name of William Crookes was one of the main contributors to the new fields of physics and chemistry that emerged in the late 19th century. Crookes’ analysis of the photographic process in the 1850s inspired his work in the science of spectroscopy. Using techniques of spectroscopy Crookes discovered the element thallium. His efforts in discovering the weight of thallium in an evacuated chamber led to his research in vacuum physics.
Ernest Rutherford was a New Zealand born British physicist who is famously known for “splitting the atom.” His work on the gold foil experiment contributed greatly to the model of the atom and helped develop the standard model of the atom to what we now use today. Without his contributions we would still be using the Plum Pudding model, an out dated and incorrect model, and we would have less of an understanding of how atoms form the world around us.
Giacomo Luigi Ciamician was a well-known professor, Italian senate member, and Italian chemist who made brilliant discoveries and has many accomplishments that have impacted the way chemistry is practiced today. Ciamician was one of the founders of photochemistry. He discovered and experimented with solar energy, which is one of his greatest achievements. He also made discoveries with the periodic table that provoked questions from other scientists, causing a chain reaction of scientific breakthroughs. While Ciamician’s many discoveries mostly relate to chemistry, they vary greatly in content, showing that he was an individual of both intelligence and curiosity.
The Daltons research papers changes, he began to study and observe the physical sciences: heat conduction, gas expansion by heat, the properties of light, the aurora borealis, and meteorology. These studies helped him establish The Atomic Theory. Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass.Dalton's atomic theory also stated that all compounds were composed of combinations of these atoms in defined ratios.Dalton also postulated that chemical reactions resulted in the rearrangement of the reacting atoms. Terms atom The smallest possible amount of matter that still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons. atomic mass unit The standard unit that is used for indicating mass of an
As technology advances so do the experiments to discover more about the atom. By 1911, Rutherford disproved Thomson's plum pudding model with his gold foil experiments. He discovered that atoms are mostly empty space and deflections are caused between a repulsive force between the positively charged nucleus and the alpha particles. James Chadwick, a co worker of Rutherford, found that there was another subatomic particle located in the nucleus called the neutron. While Rutherford’s model of the atom showed the electrons orbiting the nucleus, Bohr’s model shows the electrons traveling around the nucleus, the distance of the electrons from the nucleus are determined by energy. Then in the late 1910’s, Robert Millikin calculated the mass of a single electron by performing the oil droplet
John Dalton, a British chemist and physicist, that was born on the 6th of September 1766. His study of gases led Dalton to wonder about what these invisible substances