There are 118 elements in the periodic table, each with a unique symbol and atomic number. Symbol: A one or two-letter abbreviation used to represent the element. Atomic number: The number of ...

One of the reasons promethium was so elusive for a relatively low atomic number element is that it doesn't have a stable state - it's one of only two elements below 83 that only has radioactive ...

organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic number. Scientists use the periodic table to quickly refer to information ...