The periodic table organises all of our discovered elements into rows (or periods) in order of increasing atomic number, and columns (or groups) where the elements have similar properties.
Metal elements are found on the left hand side of the periodic table, and non-metal elements are found on the right.
There have been many scientists that worked on developing a chart of elements, but most notably Russian chemist Dmitri Mendeleev published his version in 1869, leaving gaps for future discoveries and developments. Mendeleev is often credited as being the creator of the modern periodic table that we know and use today.
In 1955, the 101st element was named Mendelevium in his honour.
With over 150 years of continuous development and research, the periodic table currently has 118 known elements, and is widely regarded as one of our most significant scientific achievements.