Question

Is Oxygen A Metal Or Nonmetal?

Answer 1

Hint : Periodic table is in a table form in which all the known (discovered) elements are arranged according to their atomic numbers, chemical properties and electronic configuration. The table has seven rows which are known as “periods'' and eighteen columns which are known as “groups”. The elements are further divided into metals, nonmetals and metalloids.

Complete Step By Step Answer:
We know that, in a periodic table, all the known (discovered) elements have been arranged in the seven periods (rows) and eighteen (columns) of the table according to their atomic numbers, chemical properties and electronic configuration.
The elements are further divided into metals, nonmetals and metalloids.
Metals have larger size, their electronegativity is low and hence, their ionization enthalpy is low (which means they can easily donate electrons).
Non-Metals have smaller size, their electronegativity is high and hence, their ionization enthalpy is high (which means they cannot easily donate electrons).
Metalloids are elements which have intermediate properties.
Now, we should know about some periodic properties, which are:
On moving from left to right in a period, size of the element decreases and it’s electronegativity increases. So, we can say that, on moving from left to right in a period the non-metallic character of an element increases.
On moving down the group the size of elements increases and their electronegativities decrease. So, their ionization energy decreases and hence their metallic character increases.
So, if we look at Oxygen, it is located in the second period (smaller size as compared to other elements) and the sixteenth group which is at the right of the periodic table.
Hence, we can conclude that the size of the oxygen atom is very small and it’s electronegativity is high ( $3.44$ ) , so it will have a large non-metallic character.
Hence, oxygen is non-metal.

Note :
Number of non-metals in the periodic table is less than the number of metals. Metalloids are the elements which have intermediate properties of both metals and non- metals. Main recognized metalloids in the periodic table are boron, silicon, germanium, arsenic, antimony and Tellurium.