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Democritus
Democritus lived from 460bc to 370bc he lived in GreeceEverything is made up of atoms they are indivisible, between atoms lies empty spaces.Atoms cant be destroyed and differ in size and shape -
Robert Boyle
Robert Boyle was born in Ireland in 1627He wrote a book called ‘Skeptical Chemist’Boyle I known for his work with gases. He Built an air pump. This allowed him to discover many things about air.He discovered air was needed for burning, breathing and for sound.Working with gases made him come to a conclusion. Because of the nature of gases, he believed in the corpuscular agreeing with democritus -
John Dalton
Dalton was born on the 6/9/1766Dalton’s theory was built on the idea that the atoms of different elements could be not able by differences in their weights. All matter is composed of atomsAtoms cannot be made or destroyedAll atoms of the same element are identicalDifferent elements have different types of atomsChemical reactions occur when atoms are rearrangedCompounds are formed from atoms of the constituent elements.Using the theory he updated the various laws of chemical combinations -
Micheal Faraday
Michael was born in Hampshire 22/9/1791In the 1830s Michael began to realize how important the electrical forces in compounds were. In a experiment involving electricity passing among electrodes in an aqueous solution. He understood that the current undid the link of atoms and that the amount of deposited material straight proportional to the amount of current flowing through the solution.This confirmed the idea that electrical forces held atoms together -
James Clerk Maxwell
James was a Scottish Physicist born in 1831James principal input to the atomic concept had to do with his theory of electromagnetism.He’s laws predict that any system in which a charged particle orbits about an oppositely charged particle should produce light at frequency related to the radius of the orbiting particle. In the case of an orbiting electron would spiral into the nuclease in a very quickly. -
Dmitri Mendeleev
Dmitri was born in 1834He revolutionized our understanding of the properties of atoms and created the table that could be sitting in your classroom.In the late 1860’s Dmitri began working on his greatest achievement, the periodic table of elements.He did it by arranging all of the 63 elements known by their atomic weights.Were a gap was present he predicted new elements would one day new elements would fill these gaps, he was right. -
Eugen Goldstein
Eugen was born in 5/9/1850He discovered protons in Anode ray experiments.According to him, atoms contain positively charged particles called protons. Since atoms contain negatively charged particles, they must contain positively charged particles for there to be a neutral particle. -
Richard Abegg
Abegg lived from 1869 to 1910He concluded that noble gases were stable because there were 8 electrons in the outermost shell.He proposed the valence bond theory. Which explained how atoms bond with each other. It led the way to understanding the rule of ionic bonding. Abegg was killed, so his theory had to wait for someone to continue the work. -
Ernest Rutherford
Ernest was born on the 30th August 1871.He worked on radioactivity, inventing the names ‘alpha’ and ‘beta’ to describe the two different types of radiation produced by uranium and thorium.IN 1907 he carried out an experiment called Geiger-Marsden. It was an attempt to examine the atoms structure. The results of the experiment showed the existence of the atomic nucleus and became an integral part of the Rutherford model of the atom. -
Fredrick Soddy
Fred was born on the 2nd September 1877.He proposed that the same elements exist in different forms, with nuclei having the same number of protons but different number of neutrons.His theory of isotopes explains that different elements can be chemically vague but have different atomic weights and characteristics.His theory was controversial among scientists until James Chadwick discovered neutrons. -
Albert Einstein
Albert was born in 1879.He proposed a new way to put the kinetic theory in a new crucial experiment. If tiny particles were suspended in a liquid the irregular attack by the liquid’s invisible atoms should cause the suspended particles to carry out a random jittering dance. This jittery dance was called the Brownian motion. He reinforced the kinetic theory and had a powerful new tool for studying the movement in atoms. -
Hans Geiger
Hans was born in Neustadt-an-der-Haardt, German, on September 30, 1882.He devised the first version of the Geiger counter to count the number of alpha particles and other ionizing radiation. With the help of other counters, he used his counter in early experiments that led to the identification of alpha particles as the nucleus of the helium atom. -
Neils Bohr
He was born on 7th October 1885.He assumed that electrons travelled in fixed orbits around the atoms nucleus and further explained how electrons absorb energy. His atomic diagram held that the outer orbits hold more electrons that inner orbits, and that these orbits determine chemical properties of an atom.His theory was expanded by other physicist formed on the basis for developing science of quantum mechanics. -
James Chadwick
Chad wick was in Cheshire, England on the 20th October 1891.He made a fundamental discovery; he proved the existence of neutrons.He predicted the atom would have a neutron. He established the numbers of protons in an atom determines that atomic number. He discovered the fourth subatomic particle, the neutron. -
Aristotle
Aristotle was born in 384bc in Stagira, Greece Aristotle could not see how atoms could stay in never changing state so he develop a theoryAristotle believed in his theory that all matter was made up of four elements fire, water, earth and air.There was also four qualities to the elements dryness, hotness, coldness and moistness
