One hundred fifty years after Russian chemist Dmitri Mendeleev published his system for neatly arranging the elements, the periodic table it gave birth to hangs in every chemistry classroom in the ...

The table is called the periodic table because elements with similar properties occur at regular intervals. The high relative abundance of these tellurium isotopes gives tellurium the greater relative ...

in older periodic tables, group numbers 1-7 and 0 are given for the main groups in newer periodic tables, ‘IUPAC’ group numbers 1-18 are given for all the groups Hydrogen, H, is placed above the top ...

Creating mnemonic phrases can help you remember the order of elements, especially for the first 20 elements or specific groups. These phrases are general and are available on other free online sources ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...