It lists all the chemical elements that exist in nature, such as hydrogen, helium, oxygen, nitrogen, zinc, copper and gold.
The way the elements are listed shows how they are categorised
and interrelated by type and characteristics. The rows are
"periods" (numbered down the left side) and the columns are
"groups" (labeled across the top). Each element is listed by its
symbol and its atomic number, and the table is often colored to
show related groups and subgroups.