What does the Periodic Table of Elements look like today?
About 50 years after Mendeleev, chemists discovered protons and the atomic number. Today we use the atomic number rather than mass to determine the order of the elements. The atomic number is always a whole number (you can’t have half a proton!) and there is an element with every atomic number up to 116, so this is a very easy way put the elements in order. All of the naturally occurring elements have been filled in, and artificial ones are added as they are created. To print out a copy, please use this link: Periodic Table of Elements You may be wondering why there are two rows at the bottom which aren’t connected to the others. They are there because they have been pulled out of where they should go in order to make the table smaller and easier to print on a page. The first picture below shows what the table should really look like. The two rows that have been moved are circled. Notice that if you follow the atomic numbers on a regular table, they go 55,56,57,72,73,74. This is becaus
