True or false? The maximum covalency in $ {2^{nd}} $ period elements is $ 4 $ . Why is this true if fluorine can only make one bond?

Hint: Chemical elements are the purest form of atoms, whereas atoms are tiny particles consisting of subatomic particles. Covalency is defined as the number of electrons that were involved in the bond formation with the other atom. $ {2^{nd}} $ period elements mean the elements from atomic number $ 3 $ to $ 11 $ . Out of these elements carbon exhibits the covalency of $ 4 $

Complete answer:
Periodic table is the representation of chemical elements arranged in the increasing order of atomic numbers. These elements are arranged in the vertical columns and horizontal rows. The vertical columns were known as groups and the horizontal rows are known as periods. There are a total of $ 7 $ periods and $ 18 $ groups.
The elements belonging to $ {2^{nd}} $ are the elements from atomic number $ 3 $ to $ 11 $ . The elements are lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon. Out of the elements belonging to the second period, carbon exhibits the maximum covalency of $ 4 $ as the valence electrons of carbon are $ 4 $ it forms bonds with other $ 4 $ atoms. Whereas the covalency of remaining elements is less than $ 4 $ .
Covalency is defined as the number of shared electrons formed by an atom of that element.
Fluorine is the element with $ 7 $ valence electrons. But it exhibits the covalency of $ 1 $ as it is only one electron deficient to attain inert gas configuration.
The maximum covalency in $ {2^{nd}} $ period elements is $ 4 $ is true.

Note:
The elements are lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon. The valence electrons play an important role in calculating the covalency. Due to this fact, carbon has maximum covalency of $ 4 $ as the number of electrons shared by carbon are four.