History Of The Periodic Table

Question 1

John Dalton

Answer 1

In 1803 he published the first list of elements when he wanted to make an easier system to write down elements, his original list consisted of 5 elements: H,O,N,C,S and their atomic weights. His work with relative atomic weights prompted him to construct the first periodic table.

Question 2

John Newlands

Answer 2

In 1864 Newlands arranged all the elements known at the time in order of atomic mass. He discovered a pattern in which each element was similar to the element eight places ahead of it. His table showed a periodic pattern of properties, this eventually broke down because ordering strictly by atomic mass, elements were in groups that did not match their chemical properties, for this reason his table wasn’t accepted by many Scientists.

Question 3

Dmitri Mendeleev

Answer 3

In 1869 he devised the periodic classification of chemical elements, in which the elements were arranged in order of increasing atomic weights. As the father of the periodic table he incorporated more elements into the table, doing a better job of putting them in the correct spots. Each group contained elements of similar properties, his table could be used to predict unknown elements and their properties.