what does the column in the periodic table mean
Periodic table The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties, whose adopted structure shows periodic trends. Generally, within one row (period) the elements are metals on the left, and non-metals on the right, with the elements having similar chemical behaviours being placed in the same column. Table rows are commonly called periods and columns are called groups. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are halogens; and group 18 are noble gases. Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals.
History of the periodic table The history of the periodic table reflects over a century of growth in the understanding of chemical properties. The most important event in its history occurred in 1869, when the table was published by Dmitri Mendeleev,[2] who built upon earlier discoveries by scientists such as Antoine-Laurent de Lavoisier and John Newlands, but who is nevertheless generally given sole credit for its development.