Final answer:
The VSEPR (Valence Shell Electron Pair Repulsion) theory is used to determine Molecular Geometry, which explains the three-dimensional arrangement of atoms within a molecule. CO₂ is an example with a linear geometry and a 180-degree bonding angle, whereas CH₄ has a tetrahedral shape with 109.5-degree angles.
Step-by-step explanation:
The theory used for determining Molecular Geometry is the Valence Shell Electron Pair Repulsion (VSEPR) theory. This theory states that electron pairs around a central atom tend to repel each other and will therefore arrange themselves as far apart as possible in three-dimensional space to minimize repulsion, which determines the geometry of the molecule.
An example of molecular geometry is the carbon dioxide (CO₂) molecule, which has a linear molecular geometry. The bonding angle in a linear molecule like CO₂ is 180 degrees.
Another example of molecular geometry is methane (CH₄), which has a tetrahedral shape with bonding angles of 109.5 degrees.