Answer
The periodic table is the arrangement of elements in order of their increasing atomic number. Elements with similar properties are grouped together under the same column.
Work Step by Step
In the periodic table elements which have similar chemical and physical properties are placed under the same column.
The Group 1 elements have an outer shell electronic configuration of $ns^{1}$.
They tend to lose 1 electron in order to achieve noble gas configuration.
Example- Li, Na, K etc.