History of the Periodic Table: Difference between revisions

Although Mendeleev's periodic table was brilliant, there were still some things wrong about it. The way that the elements were arranged still did not always group the elements that were similar. One of Ernst Rutherford's assistants, Henry Moseley, suggested that they develop a way to count the number of protons in an atom's nucleus. Once he created a way to do this, he realized they needed to revise the periodic table to make it more accurate, now that they could find the number of protons in an atom. He changed the periodic table and the periodic law. The modern periodic law states, ''The properties of elements vary with their atomic numbers in a periodic way''. <ref name=BJU/>  

The modern periodic table has more than the 63 elements that were discovered by Mendeleev. Most of the periodic tables up to this date have up to 109 elements. It has 18 groups in vertical columns. The vertical columns are labeled by roman numerals or numbers, and each horizontal row is called a period, and the periodic table consists of seven periods. <ref>GENESIS. [https://genesismission.jpl.nasa.gov/educate/scimodule/cosmic/explore_2ST.pdf Cosmic Chemistry: An Elemental Question] ''Genesis Education''. Accessed May 21, 2017.</ref> On the left and middle side of the table there are the elements that are metals. On the right side are the nonmetals, groups 13-18. The metalloids are adjacent to the stair-step line on the table. On the bottom of the table are the tow rows of elements called the lanthanide series and the actinide series. The atomis number increases from left to right along the whole periodic table, and become less metallic.