Draw the Lewis structure for BF3
(boron trifluoride). Choose a fill-in answer from the drop down menu for each statement.
There are/is bond(s) present in the Lewis structure.
The bond(s) are/is classified as
The central atom obeys the octet rule.
BF3 is classified as a compound.
BF3 does display resonance structures.
The Correct Answer and Explanation is:
Sure! Here are the correct answers for each statement about the Lewis structure of BF₃ (boron trifluoride):
- There are/is bond(s) present in the Lewis structure.
Answer: 3 bonds - The bond(s) are/is classified as
Answer: covalent bonds - The central atom obeys the octet rule.
Answer: No - BF₃ is classified as a compound.
Answer: Yes - BF₃ does display resonance structures.
Answer: No
Detailed Explanation (300+ words):
The Lewis structure of boron trifluoride (BF₃) consists of a central boron (B) atom bonded to three fluorine (F) atoms. Each fluorine atom forms a single covalent bond with boron, so there are 3 bonds in total.
Boron has 3 valence electrons, and fluorine has 7 valence electrons. When drawing the Lewis structure, each fluorine shares one electron with boron, forming three single covalent bonds (B–F). Each fluorine completes its octet by having three lone pairs of electrons around it.
Bond type: The bonds between boron and fluorine are covalent bonds because they involve the sharing of electrons between atoms.
Octet rule for central atom: Typically, atoms in covalent molecules try to satisfy the octet rule, meaning they have eight electrons around them for stability. However, boron is an exception. In BF₃, boron has only six electrons around it (three single bonds × 2 electrons per bond = 6 electrons), not eight. Boron is stable with this incomplete octet because it is an electron-deficient element and is stable with less than eight electrons in certain compounds. Thus, the central atom (boron) does not obey the octet rule in BF₃.
Classification: BF₃ is a compound because it consists of two or more different elements chemically combined.
Resonance structures: Resonance occurs when multiple valid Lewis structures can represent the molecule, usually involving the shifting of electrons or double bonds. BF₃ does not display resonance structures because the three B–F bonds are equivalent single bonds, and there is no alternative bonding pattern that would redistribute electrons to form resonance forms.
In summary, BF₃’s Lewis structure features three covalent bonds, a boron central atom that does not fulfill the octet rule, no resonance, and the molecule is classified as a compound. This makes BF₃ an interesting example of an electron-deficient compound that challenges the usual octet rule convention.