Textbook Question
How many valence electrons does each of the following contribute to a Lewis structure?
(i) Cl
909
views
1. A Review of General Chemistry
Lewis Structure
2:06 minutesProblem 59d
Textbook Question
Which atom in each pair would you expect to be the central atom in a Lewis structure?
(d) C vs. N
Verified step by step guidance1
Identify the general rule for selecting a central atom in a Lewis structure: The central atom is typically the least electronegative atom, as it is more likely to share electrons with surrounding atoms.
Compare the electronegativities of carbon (C) and nitrogen (N). Carbon has an electronegativity of approximately 2.55, while nitrogen has a higher electronegativity of approximately 3.04.
Since carbon is less electronegative than nitrogen, it is more likely to serve as the central atom in a Lewis structure.
Consider the valency of each atom. Carbon has four valence electrons and can form up to four bonds, making it versatile as a central atom. Nitrogen, with five valence electrons, typically forms three bonds and is less commonly the central atom unless the molecule's structure requires it.
Conclude that carbon (C) is the preferred central atom in this pair for most Lewis structures, based on its lower electronegativity and bonding versatility.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
2mKey Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Lewis Structures
Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They help visualize the arrangement of electrons and the connectivity of atoms, which is crucial for predicting molecular geometry and reactivity.
Recommended video:
Guided course
04:12
Drawing the Lewis Structure for N2H4.
Central Atom
The central atom in a Lewis structure is typically the atom that can form the most bonds or has the highest valence. It is usually the least electronegative atom in a molecule, as it can effectively bond with surrounding atoms to achieve a stable electron configuration.
Recommended video:
Guided course
01:44The difference between atomic numbers and atomic mass.
Electronegativity
Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond. In determining the central atom, the atom with lower electronegativity is often preferred, as it is more likely to share its electrons and form bonds with other atoms.
Recommended video:
Guided course
1:47Electronegativity
Related Videos
Related Practice