What is the formula mass of the iodine molecule?

Hint :Iodine has a chemical symbol ‘ $ I $ ’. It has atomic number 53 which is denoted by the symbol ‘Z’. It is a non- metal which is present in the p- block of the periodic table. It exists in the molecular form as $ {I_2} $ which is known as the Iodine molecule. Molecular weight of any molecule is calculated by multiplying the atomic mass of one atom by the total number of atoms in the molecule.

Complete Step By Step Answer:
Iodine is a non-metal present in the p-block of the periodic table. It is denoted by the chemical symbol ‘ $ I $ ’. It has atomic number 53 which is denoted by the symbol ‘Z’.
Now, we will see the period table:-

In the above periodic table, The elements in the yellow coloured boxes from group $ 13 $ to group $ 18 $ are known as p-block elements or main-group elements. Their general electronic configuration is $ n{s^2}n{p^{1 - 6}} $ .
The Iodine element is present in the fifth period and seventeenth group of the periodic table. It is a member of the halogen family.
Iodine exists as a $ {I_2} $ molecule in the molecular form. Hence, there are two iodine atoms in the molecule of iodine. Molecular weight ( which is also known as formula mass)of any molecule is calculated by multiplying the atomic mass of one atom by the total number of atoms in the molecule.
Atomic mass is denoted by A. Atomic mass of Iodine is $ 126.9gmo{l^{ - 1}} $ .
An iodine molecule contains two iodine atom and hence, we can calculate Formula mass of iodine molecule as:
 $ = (126.9 \times 2)gmo{l^{ - 1}} $
 $ = 253.8gmo{l^{ - 1}} $
Therefore, the formula mass of an iodine molecule is $ 253.8gmo{l^{ - 1}} $ .

Note :
Iodine has many applications in our lives. Iodine is used in disinfectants, dyes, pharmaceuticals, catalysts and animal food. It is also used to make polarising filters for LCD displays. Iodine deficiency can affect the thyroid gland and hence it is added in small amounts to table salt, so that we can intake it.