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460
Democritus
Democritus lived from 460 BC to 370 BC in Greece. He was known for proposing hypotheses based on thought and reasoning rather than carrying out experiments. He is also well known for this quote: “By convention there is colour, by convention there is sweetness, by convection there is bitterness, but in reality there are atoms and the void”. This means that he believed that senses were purely imagination, but atoms were real. -
Jan 1, 600
Kanada
Kanada was a philosopher from 600 BC. He believed everything was divided and divided and divided until it was indivisible, which he called paramanu. He believed it was indestructible. He stated that each paramanu has a specific property that is same as the class of substance to which it belongs to. He also discovered if two paramanu belonging to one class of substance combined, a devinuka is produced. -
Jan 1, 624
Thales
Thales lived from 624 BC to 546 BC in Greece.He proposed the idea that water was the origin and basis of all matter. Although this does not seem to be correct, there is some truth in it that helped the growth of the atomic model. Water is necessary to life, and the first life forms came from the oceans, so scientists understood his ideas and used them to develop their own atomic theories. Thales's water based theory was not disproved until the 1700’s. -
Isaac Newton
Isaac Newton was born on the 25th of December 1642 in Lincolnshire, England and died on t20th of March 1727 in Kensington, England. Isaac Newton invented calculus, the reflecting telescope, and worked out scientific principles such as the three laws of motion and the laws of gravity (showed that all objects in the universe attract each other through gravitational force). This is beneficial, especially in mechanics and space travel. This shows how much of an impact Isaac Newton had on Science. -
Antoine Lavoisier
Antoine Lavoisier lived August 26th, 1743 to May 8th 1794 in France. He studied the composition of chemical compounds, discovering that compounds containing more than one element always had the same amount of each element. -
John Dalton
John dalton was born on the 6th of September 1766 and died on the 27th of July 1844.
John Dalton’s Atomic Theory:All matter is made of atoms.Atoms are indivisible and indestructible.All atoms of a given element are identical in mass and properties.Compounds are formed by a combination of two or more different kinds of atoms. A chemical reaction is a rearrangement of atoms. -
Robert Brown
Robert Brown lived from December 21st 1773 to June the 10th 1858. Robert Brown performed an experiment where pollen grains were put on water and observed, to find that the pollen grains constantly changed directions in random patterns as if bumping into something invisible. Brown discovered that the explanation to this was that the pollen was hitting particles of water - causing the movement. This movement has been named the Brownian motion, after Robert Brown. -
Joseph Thomson
Thomson was born on December 18, 1856, in England and died August 30th, 1940. After Dalton suggested his theory, Thomson discovered that atoms were actually divisible and were made up of smaller particles. He discovered that all atoms have electrons, which he assumed were floating all around the inside of the atom, like fruit in a plum pudding, which was false. Thomson was also the first person to suggest the theory of the atom containing positive and negative particles. -
Ernest Rutherford
Ernest Rutherford was born on the 30th of August, 1871. He died on the 19th of October 1937. What Rutherford discovered changed the layout of an atom and how we think about it entirely. He discovered that there is a nucleus in the center of an atom, as well as that, an atom is mostly empty space with a large amount of positive charge. He is famous for the gold foil experiment, which helped him to understand the interior of an atom. -
Niels Bohr
Niels Bohr was born on the 7th of October 1885, and died on the 18th of November 1962. He received a Nobel Prize for physics in 1922. Bohr studied the structure of an atom. In 1911 he determined how electrons move around the nucleolus at an exact distance. He worked out the more energy the electron has, the further away it orbits. He suggested that electrons didn't spiral into the nucleus, but orbit in different levels. This is called the Bohr model, or the quantum model. Outer orbits can hold -
Erwin Schrödinger
Erwin Schrödinger was born on August 12, 1887 and died 4 January 1961. Schrödinger was an Austrian scientist famous for creating a mathematical equation to understand how electrons act in the hydrogen atom. Erwin received the Noble Prize in 1933 in physics. -
Henry Moseley
Henry mosely was a British chemist who lived from November 23rd 1887 until August 10th 1915. Moseley developed the application of x-ray spectra to study the structure of an atom. He discovered that the number of protons in an element determines its atomic number. This caused the positioning of the periodic table to be more accurate, because of a closer determination of each elements atomic numbers. his is still used in everyday science in today’s society. -
James Chadwick
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Enrico Fermi
Enrico Fermi was born in Rome on the 29th of September 1901 and died on the 28th of November 1954. He was an Italian theoretical and experimental physicist. It was 1926 when he discovered the statistical laws (Fermi laws), which are the particles subject to fermions. He progressed the beta decay theory by merging previous work done on the radiation theory using Pauli’s idea of neutrino. -
Empedocles
Empedocles is an ancient Greek philosopher, born in 490BC and died in 430BC. Empedocles is generally considered the last Greek philosopher to record his ideas in poetry. Some of his work survives, more than in the case of any other Pre-Socratic philosopher. He published a poem on nature that insisted that everything contains the four elements “fire, earth water and air.” -
Aristotle
Aristotle lived from 384BC – 322BC. He made a difference to today’s knowledge of science because his works contain the earliest known formal study of logic, which was incorporated in the late 19th century into modern formal logic. Aristotle suggested that all matter was made of earth, fire, air, water and ether. These were controlled by love and hate. This was a popular theory to what matter was made of because people found it easy to relate to.