1.2 Chemical Bond: Molecular Geometry Flashcards
What is a Lewis structure?
It is a representation that shows the distribution of electrons in a molecule formed by covalent bonds, where a shared pair of electrons is indicated with lines or as pairs of dots between two atoms, and the unshared lone pairs are indicated as pairs of dots on individual atoms.
What is formal charge?
The formal charge helps determine the distribution of electrons in a molecule or ion. It represents the charge that an atom in a molecule would have if all the bonds in the molecule were covalent and the electrons were shared equally.
How is formal charge related to Lewis structures?
The formal charge helps determine the stability of a Lewis structure.
Structures with formal charges close to zero are more stable and preferable.
High formal charges may indicate that the structure is not the most appropriate.
What is a resonance structure?
A resonance structure is one of two or more Lewis structures for a single molecule that cannot be adequately represented by a single Lewis structure
Example: Ozone (O₃)
What is molecular geometry and how many forms are there?
Molecular geometry refers to the three-dimensional arrangement of the atoms in a molecule.
Molecular Shapes:
Linear: 180° (Example: CO₂)
Trigonal Planar: 120° (Example: BF₃)
Tetrahedral: 109.5° (Example: CH₄)
Trigonal Bipyramidal: 90° and 120° (Example: PCl₅)
Octahedral: 90° (Example: SF₆)
Angular or V-Shaped: <120° or <109.5° (Example: H₂O)
