Question

How many valence electrons do the halogens possess?

Answer 1

Halogens, which include elements like fluorine, chlorine, bromine, and iodine, have seven valence electrons. They tend to form diatomic molecules with a single covalent bond and three lone pairs of electrons to fulfill the octet rule.

Step-by-step explanation:

The halogens belong to Group 7A (or Group 17 using the IUPAC nomenclature) of the periodic table. These elements, which include fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), each have seven valence electrons in their outermost electron shell. The electron configuration for these valence electrons is typically represented as ns²np⁵. Due to having seven valence electrons, halogens are one electron short of having a complete octet, which makes them highly reactive as they tend to gain one electron to achieve a stable noble gas electron configuration.

Halogens commonly form diatomic molecules, such as F₂ and Cl₂. In these molecules, a single covalent bond is formed between two halogen atoms, completing the octet for each. Additionally, each halogen atom has three lone pairs of electrons. The high electronegativity and the presence of seven valence electrons are key to their reactivity and chemical behavior.

The octet rule explains this valence electron arrangement, showing how main group elements tend to form enough bonds to obtain eight valence electrons, akin to a noble gas electron configuration. The octet rule is a fundamental principle in understanding chemical bonding for many elements, including halogens.

Answer 2

• The halogens posses seven valence electrons

Step-by-step explanation:

• Valence electrons are the electrons in the outermost orbitals of the atoms, which are the orbitals with the highest main energy level (principal quantum number).

• Halogens are the elements of the group 17 of the periodic table: F, Cl, Br, I, At.

• You can tell the number of valence electrons of the representative elements from the number of the group to which they belong. For the representative elements, the number of valence electrons equal the unit digit of the group number.

This table summarizes it:

Group number number of valence electrons

1 1

2 2

13 3

14 4

15 5

16 6

17 7

18 8

• So, in conclusion, the halogens possess 7 valence electrons.