Answer:
The correct answer is: Hydrogen
Step-by-step explanation:
The periodic table is defined as the tabular arrangement and classification of the chemical elements. This table contains seven rows, called periods; and eighteen columns, called groups.
Generally, the metals are present on the left and the non-metals are present on the right of the periodic table.
However, Hydrogen (atomic number 1) is the only non-metal that is placed in group 1, on the left-side of the periodic table. This is because according to the electronic configuration of hydrogen (1s¹), it should be placed in group 1 of the periodic table.