Using Lewis symbols and Lewis structures, diagram the formation of PF₃ from P and F atoms, showing valence-shell electrons. (e) Does PF₃ obey the octet rule?

Verified step by step guidance

1. insert step 1: Identify the valence electrons for each atom involved. Phosphorus (P) is in group 15 and has 5 valence electrons. Fluorine (F) is in group 17 and has 7 valence electrons.
2. insert step 2: Draw the Lewis symbols for each atom. For phosphorus, represent it with the symbol 'P' and place 5 dots around it to represent its valence electrons. For fluorine, use the symbol 'F' and place 7 dots around it.
3. insert step 3: Determine how the atoms can share electrons to form covalent bonds. Phosphorus needs 3 more electrons to complete its octet, and each fluorine atom needs 1 more electron. Therefore, phosphorus will form a single covalent bond with each of the three fluorine atoms.
4. insert step 4: Draw the Lewis structure for PF_3. Place the phosphorus atom in the center and arrange the three fluorine atoms around it. Draw a single line (representing a pair of shared electrons) between phosphorus and each fluorine atom. Complete the octets for the fluorine atoms by adding lone pairs of electrons.
5. insert step 5: Check if PF_3 obeys the octet rule. Count the electrons around each atom. Phosphorus should have 8 electrons (3 shared pairs and 2 lone pairs), and each fluorine should have 8 electrons (1 shared pair and 3 lone pairs). Confirm that all atoms satisfy the octet rule.

Key Concepts

Lewis Symbols

Lewis symbols represent the valence electrons of an atom as dots surrounding the element's symbol. Each dot corresponds to a valence electron, allowing for a visual representation of how atoms bond and share electrons. This concept is crucial for understanding the formation of molecules, as it helps illustrate the electron configuration and bonding behavior of elements.

Lewis Structures

Lewis structures are diagrams that depict the arrangement of atoms and the distribution of valence electrons in a molecule. They show how atoms are bonded together and whether they share or transfer electrons. By using Lewis structures, one can visualize molecular geometry and predict the properties of the compound, such as polarity and reactivity.

Octet Rule

The octet rule is a chemical guideline stating that atoms tend to bond in such a way that they each have eight electrons in their valence shell, achieving a stable electron configuration similar to that of noble gases. While this rule applies to many main-group elements, exceptions exist. In the case of PF3, understanding whether it obeys the octet rule involves analyzing the electron count around phosphorus and fluorine in the Lewis structure.