Question

Give the trends in the following properties of Halogens: a) Atomic number

Answer 1

Halogens:

• Seventh Group elements with a general electronic configuration of ns²np⁵ are called Halogens. They include Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At).

Atomic number:

• It is the number of protons in the nucleus of an atom. It is the identity of an element.
• atomic number=number of protons= number of electrons (neutral atom)

Reason for increase in the atomic number of halogens down a Group:

• In a long-form of periodic table, all the elements are arranged in increasing order of atomic number. Thus, on moving down a group of halogens, there is always an increase in the atomic number.

Conclusion: Hence, the increasing order of atomic number of halogens is: F < Cl < Br < I< At