The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron setup, and repeating chemical properties. The structure of the table shows occasional (popular things/general ways things are going). The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with almost the same chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks connected with the filling of different atomic orbitals.
We can sense some infrared energy as heat. Some objects are so hot they also emit visible light—such as a fire does. Other objects, such as humans, are not as hot and only emit only infrared waves.