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Democritus (400 BC)
Democritus was the first person come up with the idea that parts of matter was indivisible and unchangeable. He called these parts of matter that were indivisible “atoma” which is what started off what we now call “atoms”. Democritus’ model was the very first atomic model ever made. The model he made showed that the atom is made to be solid and indestructible. He’s model was only a basic sphere because they didn’t have microscopes to see all the electrons, protons and neutrons. -
Isaac Newton
Isaac Newton (1643) was born in Notheastern England, in the county of Lincolnshire. Most of his largest discoveries and contributions to the atomic theory were in the subjects of maths and science.
Isaac Newton came up with a thought that small solid masses in motion in a mechanical universe. Newton helped publicise that atoms affect the chemical properties of matter, which changed the atomic theory and helped us understand that atoms are what make everything work. -
Antoine Lavoisier
Antoine Lavoisier was born into a very wealthy family in Paris on the 2th of August 1743.Antoine Lavoisier was called the ‘father of science”. Antoine made a lot of amazing predictions and discoveries in his lifetime.
He discovered that water is made out of hydrogen and oxygen, which was one of his biggest discoveries. Antoine also found out a lot about chemical elements and discovered something called analytical balance. He also helped constuct the metric system. -
John Dalton
John Dalton lived in Manchester UK and he was born on the 27th of July 1844. He was a chemist and was one of the first people to design an atomic model. John believed that the atom was the smallest possible element of matter. He was then proved wrong when Thomson cameand found an even smaller component called the electron. John Dalton performed many experiments with different chemicals that showed him that matter had many particles, which were atoms. He also discovered the Dalton's Law. -
Dmitri Mendeleev
Dmitri Mendeleev (1834) was a Russian chemist and a famous inventor. He was born in a village called Verhnie Aremzyani.In 1869 Dmitri Mendeleev created the first version of the periodic table elements and used it to predict the properties of elements that were yet to be invented/discovered.Dmitri arranged all 63 elements then known by their atomic weights and if a gap existed in the table, he predicted a new element would one day be found; and he was right. -
John Thomson
Joseph John Thomson (1856). He was born in Cheetham Hill and was a British Physicist. He is known as the scientist that discovered electrons and isotopes and inventing the famous and well-known mass spectrometer. J.J Thomson’s version of the atomic theory showed that electrons inside an atom could tell us that atoms were not invisible. Thomson created a model, which was in the shape of a sphere of positive matter with negatively charged electrons surrounding them (plum pudding model). -
Ernest Rutherford
Ernest Rutherford (1891) was British chemist and physicist who became known as the father of nuclear physics. Ernest discovered many different things in his lifetime including alpha, gamma rays in radiation and beta. But one of his biggest achievements was finding out that an atom had a nucleus in the centre. Not only did he find out that but he also found out that it was (+) charged. Ernest Rutherford’s atomic model structure showed the nucelus in the center and electrons orbiting around. -
Frederick Soddy
Frederick Soddy was born on the 2nd 1877 of September and died on the 22nd of September 1956. Frederick was a English radio chemist and modern economist who worked with Ernest Rutherford and explained to us that radioactivity is the transmutation of elements which is now known to involve nuclear reactions. He also conducted many experiments, which proved the existence and came up with the term "isotopes" to explain the unintentional breakdown of radioactive elements. -
Hantaro Nagaoka
Hantaro Nagaoka (1950) was a Japanese scientist and a pioneer of Japanese physics.Though some atom models were proposed in the world of physics in the early 20th century, it was Hantaro Nagaoka, then professor at the University of Tokyo, who was the first to presented a Saturnian atomic model close to the presently accepted model.In 1903, he made a prediction that electrons orbit around a positively charged nucleus which was very similar to how the rings circle around the planet Saturn. -
Richard Abegg
Richard Wilhelm Heinrich Abegg was born in Germany on the 9th of January in 1869. He proposed the difference of the maximum positive and negative numbers in light of the newly discovered presence of electrons within the atom.He concluded that the Noble gases were stable because there was 8 electrons in the outer shell. He proposed the “valence bond theory,” which began to explain how atoms bond with each other. -
Hans Geiger
Johannes “Hans” Wilhelm Geiger (1882) was a german scientist. He was born in Germany which is a town in Germany.
Johannes “Hans” Wilhelm Geiger is largely known around the world as the co-inventor with Ernest Rutherford on the ‘Geiger Counter”. “Hans” was one Ernest’s most beneficial and productive co-workers, he worked in Manchester with Ernest Rutherford for 6 years.The Geiger Counter was made to count the number of alpha particles and was used to detect radioactivity. -
Henry Moseley
Henry Gwyn Jeffreys Moseley was an English physicist scientist. He was born on the 23rd of November 1887 and died on the 10th of August 1915. He lived in Weymouth, Dorset. In 1913, by using x-ray spectra obtained by diffraction in crystals, he found a systematic relation between wavelength and atomic number this was then called Moseley's law. Moseley’s experiment educated us in many different ways.
He showed us that atomic numbers were not subjective but could be measured. -
Niels Bohr
Neils Bohr (1855- 1962) was a Danish physicist. He contributed a lot to understanding the atomic structure and quantum. He also developed the theory that electrons travel in discrete orbits around the atom's nucleus, in specific shells. He made a model (the Bohr model of the atom) which then explained to us that the atomic nucleus was in the centre and showed the electrons that orbit around it, which he compared to the planets orbiting the Sun. -
James Chadwick
James Chadwick was born in England in 1891. He was an English Nobel Laureate in physics.James is known for his discovery of a particle in the nucleus of an atom in 1932. This particle was later called a neutron because it doesn’t have an electric charge.Chadwick’s many experiments he conducted on atoms proved the existence of the neutron which is what accelerated the research in nuclear physics immensely because before this scientists only knew of the existence of protons in the nucleus. -
G.J. Stoney
George Johnstone Stoney was born on the 15th of February and died on the 5th of July 1911. He lived in both Dumfries and Galloway in his lifetime. He was a Ango-Irish physicist and he is most famous for naming the “fundamental unit quantity of electricity” an electron. Although he didn’t actually discover an electron he proposed the term and his contributions to research in this area helped JJ.Thomson on the actual discovery of the electron in 1897.In ‘Stoney’s’ lifetime and even in a few year
