How many valence electrons surround the arsenic atom in arsenic pentafluoride
The correct answer and explanation is:
Arsenic pentafluoride (AsF₅) consists of one arsenic (As) atom and five fluorine (F) atoms. To determine the number of valence electrons surrounding the arsenic atom, we begin by considering the electron configuration of arsenic.
Arsenic belongs to Group 15 of the periodic table, so it has five valence electrons. In arsenic pentafluoride, arsenic forms five bonds with five fluorine atoms. Each fluorine atom contributes one electron for the bond, while arsenic contributes one electron per bond. Therefore, the arsenic atom shares its five electrons with the five fluorine atoms, creating five single covalent bonds.
The number of valence electrons surrounding the arsenic atom in arsenic pentafluoride can be determined by counting the electrons involved in bonding. Since arsenic contributes one electron to each of the five bonds, there are five bonding electrons.
Additionally, arsenic can accommodate more than eight electrons in its valence shell because it is in Period 4 of the periodic table. This is due to the presence of d-orbitals in its valence shell, which allows it to form more than the typical eight bonds that elements in the second period can form.
Thus, while arsenic contributes five electrons to the bonding in AsF₅, it does not retain any lone pairs of electrons. Therefore, the arsenic atom has five valence electrons surrounding it in arsenic pentafluoride. These electrons are involved in covalent bonding with the fluorine atoms.