IntroductionThe periodic table, used around the world by scientists, teachers and students, to quickly locate information about the elements. However, the periodic table did not arrive overnight, the periodic table is a table formed by years of work on atomic structure. It all started years ago with Democritus and his discovery of the atom. This was followed by John Dalton many years later, after the elements had been discovered, Dalton attempted to create a way to make the elements easier to remember. 84 years later, JJ Thomson discovered electrons, which were the key to the periodic table, and in 1889 Dmitri Mendeleev invented the periodic table. Years later Henry Moseley discovered how to measure the atomic numbers of elements, and only 9 years later Neil Bohr explained the structure of the atom which further explained why Mendeleev placed each element in a specific row or column. James Chadwick eventually discovered the neutron in 1922. Democritus In ancient Greek times in the year 460 BC, Democritus and Leucippus proposed that everything in the world was made up of atoms. He also proposed that atoms were indestructible, that there were an infinite number of them, and that there was empty space between them. Democritus formed opinions on atomic structure, such as its shapes and connectivity. Democritus also stated that atoms were different sizes, but he was unsure of the weight of the atoms. Democritus' discovery of the atom is the basis of the elements, which is the basis of the periodic table. Without the discovery of the atom, the periodic table would never exist. John Dalton In 1803, John Dalton published a list of items. He tried to create a system to make items easier to remember and write. The original...... middle of the sheet......ia Britannica. 2014. law of the eighth (chemistry) -- Encyclopedia Britannica. [ONLINE] Available at: http://www.britannica.com/EBchecked/topic/424834/law-of-octaves. [Accessed May 14, 2014]. Dmitri Mendeleev - Wikipedia, the free encyclopedia. 2014. Dmitri Mendeleev - Wikipedia, the free encyclopedia. [ONLINE] Available at: http://en.wikipedia.org/wiki/Dmitri_Mendeleev#Periodic_table. [Accessed 14 May 2014].Democritus: physics and philosophy of atomism. 2014. Democritus: Early Physics and the Philosophy of Atomism. [ONLINE] Available at: http://www.allperiodictables.com/AAEpages/aaeDemocritus.html. [Accessed 14 May 2014]. Periodic Tables by John Dalton. 2014. Periodic Tables by John Dalton. [ONLINE] Available at: http://www.sussexvt.k12.de.us/science/The%20History%20of%20the%20World%201500-1899/John%20Dalton's%20periodic%20tables.htm. [Accessed May 12 2014].